GPS trackers for cars, trailers and bikes

OBD-II dongle. Plugs into the diagnostic port under the dash, which supplies permanent power. Install time is about ninety seconds and requires no tools. It will never need charging. Two drawbacks: it is plainly visible to anyone in the driver's seat, so it is not a covert device, and it occupies the port a mechanic needs. A ten-dollar splitter extension solves both problems by moving the dongle up behind the trim and leaving the port free.

Hardwired. Spliced into a switched or permanent 12V feed and tucked behind trim. This is the right answer for anti-theft, because it cannot be found by looking and cannot be unplugged in two seconds. It never needs charging. The cost is an hour of your time with a multimeter, or an installer's fee, and it is a poor idea in a leased vehicle.

Magnetic battery pack. Stick it under the car or in the boot and you are done. It moves between vehicles freely, which makes it the only sensible choice for a trailer or a piece of plant. The cost is that you now own a thing that needs recharging, and a flat tracker is worse than no tracker because you believe you are covered.

If you want one rule: daily driver you want trip data on, buy OBD. Vehicle you are worried about losing, hardwire it. Trailer, boat, generator or anything without power, buy magnetic and set a calendar reminder.

A tracker is a recovery tool, not a prevention tool. It tells you and the police where the vehicle went. It does not stop the vehicle being taken, and in the specific case of modern keyless cars, the cheapest meaningful prevention has nothing to do with tracking at all: a signal-blocking pouch for the key fob, which defeats the relay attack used in most keyless thefts, costs less than a tank of fuel.

The one tracking feature that genuinely crosses into recovery is a remote starter disable, which stops the car being restarted after it is next switched off. It is available on hardwired units like the TrackmateGPS Mini PRO II and it is worth understanding properly before you rely on it: disabling a vehicle in motion is not something you do, and the feature is designed around preventing a restart rather than stopping a moving car.

Also worth knowing: the OBD port itself is an attack surface. On several commonly stolen models, thieves program a new key through it in under a minute. A keyed OBD port lock blocks that, and blocks someone unplugging your tracker at the same time.

Motorcycles are the hardest case here. There is no OBD port to plug into, the battery is small, and the device will be exposed to weather, so you want a waterproof hardwired unit mounted under the seat or in the tail. Battery drain matters far more than on a car: a bike that sits for three weeks with a tracker drawing current is a bike that will not start. Check the sleep behavior before you wire anything in.

Trailers have no power at all, which leaves a long-life magnetic battery unit or a prepaid-service device. If the trailer lives somewhere with phones around it, a Bluetooth tag in a magnetic waterproof case genuinely covers the common theft — you learn it left and roughly which direction — for no running cost.

RVs and boats usually do have 12V available, which means you can hardwire and stop thinking about batteries. Solar-assisted magnetic units exist for the ones that do not.

Bicycles are their own category. A plain tag hidden in a bottle-cage mount works and costs nothing to run, but a dedicated unit like the Knog Scout adds a motion alarm, which deters the opportunist who makes up most bike theft. For a motorcycle or an expensive e-bike left outside, a low-power cellular unit with a tow alert — the Invoxia GPS Tracker PRO is the obvious one — tells you something moved while you still have time to act.