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The Motoring Review

Independent tests, rankings & buying advice for Australian drivers

A mechanic's ranking: the five most popular anti-theft devices — and the one that actually stops a car being taken

James Wesson has spent twenty years repairing stolen cars. We asked him which anti-theft products are worth the money and which aren't, and to rank the five most common.

By James Wesson· Mechanic Updated July 20266 min read

A GPS tracker, Faraday pouch, car alarm siren, Ghost immobiliser unit and a yellow Lock'd steering lock lined up on a workshop bench.

I'm a mechanic in Melbourne, and for twenty years a good part of my work has been repairing cars after they've been stolen, or someone's had a go. You see enough of them and you start to notice which security products keep turning up on the cars that got taken — and which ones almost never do.

The Motoring Review asked me to rank the five most common: the TK905B GPS tracker, the Viper 3103V alarm, the Autowatch Ghost II immobiliser, a Faraday pouch, and the Lock'd steering lock. I didn't rank them on how strong they are, because none of them makes a car impossible to steal. What matters more is when each one acts. A theft runs in a sequence — a thief chooses the car, gets in, starts it, and drives off — and almost every product here only does something after the car has already been chosen. One works before that. Ranked on when they act, the order isn't the one most people would guess.

  1. 1 ChoosingFrom the footpath, before they touch itLock'd Car Defender
  2. 2 EntryGetting inViper alarm · Faraday pouch
  3. 3 Start / drive-awayOnce they're insideGhost II immobiliser
  4. 4 After it's goneRecoveryTK905B tracker
The four stages of a theft, and where each device acts.

How I judged them

I scored each one against five questions, in the order they matter to someone actually trying to keep a car:

  1. Does it act while the thief is still choosing? The earlier it works, the more it prevents a theft rather than just recording one.
  2. Does it work without you having to remember? Anything you have to arm, seal or switch on every time is only as good as the day you forget.
  3. Does it need an installer or a wait? Some go on in seconds. Others mean an auto-electrician and a booking weeks away.
  4. Can it leave you stranded? Security that occasionally locks you out has a cost of its own.
  5. Is it fair value against the everyday threat? For most people that’s the opportunist working a street at night, not an organised crew with a truck.

The five, side by side

How they compare at a glance. Full write-ups below, best first.

Scroll sideways →

Device What it does When it acts Upfront price Ongoing cost Pro install Score
Lock'd Car Defender Visible deterrent Choosing $79.99 ✓ None ✓ No 9
Autowatch Ghost II Immobiliser Hidden immobiliser Start / drive-away $600–1,200 ✓ None ✕ Yes 8
Viper 3103V Car Alarm Alarm Entry $300–600+ ✓ None ✕ Yes 5
Faraday pouch Signal blocker Entry (relay only) ~$30 ✓ None ✓ No 4
TK905B GPS Tracker GPS tracker After it's gone $150–400 ✕ Subscription + SIM ✓ No 3

Prices are indicative Australian retail, July 2026.

#1 Pick · Editor's Choice

#1

Lock'd Car Defender

Acts at: the moment of choosing

9/10
A bright yellow Lock'd Car Defender cable lock looped through a steering wheel and clipped into the seatbelt buckle.

The Lock'd Car Defender was the only product on test that acts while a car is still being chosen, rather than after a thief is already inside it. It's a high-visibility steering lock — bright yellow, visible through the windscreen from around twenty metres — and that visibility is the whole mechanism. A thief scanning a street sees it before he approaches and moves on to a car that hasn't got one. It works as a deterrent rather than a reaction.

It fits nearly any car and goes on in about five seconds, with no wiring, no professional install, and no PIN to enter every drive — the practical reasons a visible lock actually gets used rather than left in a drawer.

Of everything I looked at, it's the only one that does anything at the stage that matters most: the moment a car is chosen.

Pros

  • Only device that acts while the car is still being chosen
  • Visible from ~20m through the windscreen
  • On in about 5 seconds, no install or wiring
  • No PIN, no subscription, no professional fit
  • Fits nearly every car

Cons

  • A grinder will still cut any lock, this one included
  • Only works while it's on the wheel

Check the price →$79.99 · Free Faraday pouch · 120-day money-back guarantee

#2

Autowatch Ghost II Immobiliser

Acts at: start / drive-away

8/10
An Autowatch Ghost II immobiliser control unit fitted behind a car's dashboard.

The Autowatch Ghost II is the most sophisticated device on the list. It's a hidden immobiliser — a small unit wired into the car — and the engine won't start until you tap a secret PIN into the dashboard buttons.

So even if a thief pulls off the relay attack that steals most keyless cars, the car still won't start. And if someone gets hold of your actual keys, it's the only product here that stops them driving off.

What holds it back is timing and cost. It stays invisible and inactive until a thief is already inside trying to start the car, so it plays no part in whether the car gets chosen — by the time it does anything, a window is usually broken. It also needs professional installation, runs to several hundred dollars or more, and asks for a PIN on every drive. A strong last line of defence, not a first one.

Pros

  • Genuinely stops a thief who already has the keys
  • Widely trusted
  • Relay-proof — beats the keyless theft method

Cons

  • Invisible, so no deterrent while the car is being chosen
  • Professional install, several hundred dollars-plus, and a wait
  • PIN on every drive
#3

Viper 3103V Car Alarm

Acts at: entry

5/10
A Viper 3103V car alarm siren and control unit.

The Viper 3103V is a well-built alarm — a two-stage shock sensor, a proper siren, professionally installed. The trouble is what an alarm does in 2026: it reacts once someone is already breaking in, and a sounding car alarm now turns almost no heads.

It does nothing to stop a car being chosen, and in my experience owners disable them about as often as they rely on them. It buys the look of security more than the fact of it.

Pros

  • Well-built hardware
  • Set-and-forget once installed

Cons

  • Car alarms are widely ignored now
  • Acts only after entry
  • Needs professional install
#4

Faraday pouch

Acts at: entry (relay attack only)

4/10
A Faraday key pouch with a car key beside it.

A Faraday pouch is genuinely worth owning, and the cheapest useful thing here. For around thirty dollars it blocks the relay attack — where a thief amplifies your key's signal from inside the house and drives the car off the driveway.

Its limits are narrow but real: it only stops that one attack, only works if the key goes in every time, and does nothing about a spare key or a car broken into another way. A sensible layer, not a solution — which is why it comes free in the box with the product ranked first, rather than instead of it.

Pros

  • Blocks the relay attack
  • Cheapest useful item here (~$30)
  • Small and portable

Cons

  • Covers one attack only
  • Must be used every time
  • No help if they get in another way or grab a spare key

#5

TK905B GPS Tracker

Acts at: after the car's gone

3/10
A TK905B magnetic GPS vehicle tracker unit.

The TK905B is a recovery tool, not a deterrent. It's a magnetic GPS unit that sits under the car and reports its location to an app, on a monthly subscription. It does nothing to stop a theft — its entire job begins after the car is already gone.

Recovery has some value: about a third of stolen cars are found, and a tracker can help police get there. But it's competing for the same money as the products that actually keep a car from being taken, and on the one test that matters here — stopping the theft — it does nothing at all. Last on the list.

Pros

  • Can aid recovery and help police
  • Works without you doing anything

Cons

  • Does nothing to prevent the theft
  • Ongoing subscription and SIM
  • Only tells you where the car went

What it costs

$79.99RRP $99.99

  • Free Faraday pouch (KeySafe, $29.99 value)
  • 120-day money-back guarantee
  • 2-year warranty
  • Free tracked shipping
  • Australian-owned, Melbourne

View Lock'd Car Defender →$79.99 · Free Faraday pouch · 120-day money-back guarantee

Comments (16)

  1. Greg Mullins4 days ago

    had mine about three weeks. some little grub tried the door on my hilux last tuesday, took one look at the yellow and just kept walking. didnt even touch it. best 80 bucks i ever spent honestly

    Sandra Kelly3 days ago

    same thing happened two streets over from me. they dont want the hassle they just move to the next one that hasnt got anything on it

  2. Pete Donnelly1 week ago

    ive run an autowatch ghost for years and rate it highly, but ill admit the writers got a point i hadnt thought about. it only does anything once theyre in the car trying to start it. by then my windows already smashed. still worth having, just not the whole answer

    Marcus Hale6 days ago

    yep got mine after the last one got pinched. brilliant bit of kit but youre right, doesnt stop them having a go. window still cost me 400

  3. Wayne Fitzgerald5 days ago

    not sure id put a visible lock at number one. a determined bloke just cuts it off. id rather something hidden they dont even know is there

    Karen Sultana5 days ago

    wayne thats the bit though, the determined ones are rare. round my way its random kids and they take one look and move to the next one. different threat

  4. Bianca Cole1 week ago

    we had a viper on the old commodore. went off every time a truck rumbled past and not one person ever looked. ended up turning it off ourselves in the end lol

  5. Jason Middleton3 days ago

    nearly bought a gps tracker last year, glad i didnt. all it does is show you where its gone. thats not stopping anything

    Ruth Ashby3 days ago

    had one on my old ute. got taken, we knew exactly where it was, in a container at the port. never saw it again. recovery isnt the same as stopping it

  6. Megan Trevisan1 week ago

    genuine question because i dont know much about these. cant they just cut it off with an angle grinder in a few seconds

    Rob Fenech6 days ago

    a grinder cuts anything, no lock stops that. but the kids nicking cars round here are 16 and carrying a screwdriver not a power tool. its about not being the easy one

  7. Trevor Willis5 days ago

    is this just the old club under a new name. we had one of those in the 90s

    Dave Papadopoulos5 days ago

    its a cable not a bar, loops the wheel and clips onto the seatbelt then folds into the door pocket. the club was a pain you never had it handy. this one lives in the car

  8. Faisal Rahman1 week ago

    i just run the lot after being done twice. faraday on the keys, lock on the wheel, tracker as backup. call me paranoid but im not going through that again

  9. Marv Kessler5 days ago

    was sure 80 bucks meant junk so i nearly skipped it. the 120 day money back is the only reason i tried. two months on its still on the wheel every night, didnt send it back. does the job

  10. Janet Coleman1 week ago

    didnt think a bit of yellow cable would do much but my streets had three cars go this year and the ones with something on the wheel are the ones still sitting there. that told me enough

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What it adds up to

None of this is an argument for going without the others. Security works in layers, and bodies like the RACV and Victoria Police recommend a visible lock alongside an immobiliser, not instead of one. But layered or not, four of these five only act once a car has already been chosen. That first stage — the decision a thief makes from the footpath — is the one almost everyone leaves open, and it’s the one the top pick covers.

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