[aaronbeekay]

I work at a major American automotive OEM on entry and starting systems. Yes, many passive-entry/passive-start systems (like those that use door handle sensors to trigger an unlock) are vulnerable to relay attacks. Relay attacks are separate from re_p_lay attacks, as you note.

Relay attacks on keyfobs seem to be much more common in the UK than in the US. Some manufacturers now include accelerometers in their keyfobs to mitigate the risk, as one of the most common attacks is stealing a vehicle out of a driveway when somebody has left their keys on a hook inside the house. With an accelerometer in the keyfob, it will refuse to authorize starting if it hasn’t been jostled recently.

[aidenn0]

In the US, I've seen relay attacks used to steal items from cars rather than the cars themselves. Either because police follow up much more vigorously on theft of cars vs petty theft of things in cars, or because it's harder to convert a stolen car to cash than it is to convert the stuff in it (which might even be cash) to cash.