The future is probably going to involve simply having all cameras on the streets look out for the numberplate as soon as its reported missing.
90% of car thieves aren't going to invest $100 in a fuzz box. If they had $100, they'd blow it on skag and not need to steal the car.
From the comments on this post, it seems to me there's a big difference between US and EU car thieves. At least in Eastern Europe and Russia thieves are not just opportunists. They are organized gangs and they've got lots of 007-style equipment.
Here the stock alarm/immobilizer in cars is considered worthless. If you want to keep having a car you either park it on secured lot, or install a good security system.