Hacker's delight.
no kidding.. it wouldn't be hard to have something to capture the signal to open the car doors and start the engine. anyhow i wouldn't trust anything to be controled by a radio freq. anyhow.. it never works.. for example the garage door openers (pardon my spelling) people are robbing houses by duplicating the garage door opener signal.
-soldier
I know one lady get robbed several times by people scanning and duplicating codes on the garage opener. There are no garage openers manufacturers who have a "real" crypto challenge/response system. Most just give the code number and the opener verifies that that 8-24 bit code is correct -- real easy to scan or duplicate. The key switches/emergency latches are very easy to bypass as well. The latch can be pried off and these code things can be pried off and bypassed with a simple hot wiring. They don't know anything about tamper switches.