Two keyless cars, one Leighton Buzzard driveway

Most households around Leighton Buzzard and the LU7 villages run two cars, and a good many of them now have two keyless ones. That is a different situation from having one, and not simply because there are two things to lose.

Start with the arithmetic that nobody does. Two cars usually means four fobs — two in use and two spares. The two in use are wherever the adults leave them, which in most houses is the same bowl, hook or worktop near the front door. The two spares are somewhere less considered: a kitchen drawer, a filing box, a bedside table. Every one of the four is broadcasting, and a relay device does not need to be pointed at a specific one. It picks up whatever is closest to the wall it is held against and repeats it. Four keys in a house is four chances that one of them is near enough.

Then the part that actually changes the risk, which is not arithmetic at all. A driveway with two vehicles on it is a better prospect than a driveway with one. Somebody deciding whether a street is worth a visit is weighing effort against return, and a property that offers two cars for one trip, one set of walls to work against and one household to avoid waking, is a more attractive proposition than a house with a single vehicle. The newer estates locally are built exactly this way — two parking spaces at the front, the front door between them, and the keys a few feet inside it.

There is a habit that makes it worse, and almost every two-car household has it. Because one car is the good one and the other is the runaround, people protect the good one. The pouch is bought for the newer car's key. The thinking about where keys live applies to that fob. The older car's key carries on living wherever it always has — which is often nearer the door, because it is the one grabbed on the way out for the school run.

That is a problem, because in a two-car theft the vehicles are frequently taken together, and because the older car is a perfectly good target on its own. If it predates keyless entry it is exposed through the diagnostic socket instead, which needs a moment in the cabin and about a minute of work. Protecting one car on a driveway and not the other is closer to protecting neither than people assume.

The other two-car-specific thing worth mentioning is that families share drivers. Both adults drive both cars; often a teenager drives one of them. Whatever you do has to work for everybody, or it gets bypassed. That is an argument for keeping any sequence short and teachable rather than clever, and for using valet mode when somebody occasional needs the car rather than handing out the sequence permanently.

The practical answer for a two-car household is not complicated. Deal with all four keys rather than the two you think about — pouches for the spares as well, and a decision about where the spares live that is not "the drawer by the back door". Then, if you are going to fit anything, fit it to both. Doing them in the same visit is cheaper than two separate bookings, and it removes the awkward outcome where the one you did not protect is the one that goes.

A Ghost II or a CAN Phantom sits on each car's own data network and will not let the engine fire until its sequence is entered. You can use a different sequence on each vehicle or the same one on both, and we will talk you through which is more sensible for your household before we set anything. Send us both registrations and we will confirm what suits each car, with a written price for the pair before anything is booked. We cover Leighton Buzzard, Linslade, Heath and Reach, Stanbridge and Billington.