Car audio getting more complex..

In most GM vehicles you can remove the radio and the car WILL still start!! I deal with these vehicles everyday, maybe one or two of the 05' models will do this, but i have not seen or heard of any yet. You will lose the chime functions and in most of the cadillacs the battery will die after several hours because the digital bus will not go to sleep. Soundgate and other various manufacturer's make interface to retain chime functions of the GM vehicles.

Jazzy

Hey hotwaterwizard, you CAN remove the radio from GM vehicles and they will still start. Most GM vehicles you will lose the chime functions which you can get interfaces to retain those chime functions. Soundgate makes them along with other manufacturer's. On some vehicles like the Cadillacs your battery will die after several hours and you might get engine and tranny trouble codes. Some of the O5 models like the Malibu Maxx you will lose other functions of the vehicle also, have to relocate the factory radio in those vehicles.

Jazzy

When I worked at a GM dealer as a lube tech....

All latest gen impalas (W-body platform FWD ones) and a few N-bodies and such, actually have the oil light reset function, and a few other resets in the factory stereo....all 2001 or newer j-bodies I believe won't start without the factory stereo....my friend has an aftermarket deck in his 2001...the factory deck is hidden behind his trunk carpet wired in parallel....not to the speakers, but it turns on.