How'd you mean "blast the area", Mr Red?

Basically a high powered transmitter. Given that key fob only has a lithium button cell the signal strength of the fob is milliwatts so a few watts from a carrier frequency TX would overload the receiver in the car and only has to transmit for about 20 seconds while the car owner walks away. Coming home or shopping, the car owner's mind is already at the target, and expecting a fob press to just do its job, and may not listen for the beep.

The examples I have seen on CCTV were at night and on-street parking but if the crims think there are goodies in the car they just return when the owners are probably asleep.

FWIW my new(ish) car is the first time fob/key thingy, and in unfamiliar locations I check the door handles. It's not the cost of any losses, it is being stranded and all the hassle that ensues that motivates my actions.