use the key they gave you (or the spare) if either one will actually turn and unlock the steering column, then pop out the fuse panel and hot wire it. there are two points with nothing connected that will do this. They are probably different on yours than mine so you should look it up. But I did this on accident when I was installing my alarm, probing the different contacts to see when i'd get power all the time and bumped another one and it started the car.... this is of course if you want to drive it to the GM service place and have em do it. you could just disable the system...

 

This won't work though. That is what the VATS is for, so you can't hotwire the car. It probably worked for you because you had your key in the ignition and it was reading the proper resistance.

I don't know if this would help, but you can actually disable your VATS a pretty easy way, but it does require it to read the proper resistance at one point. If you start the car with the correct resistor in place, and then take it out with the car still running, it will think that the VATS has malfunctioned, thus disabling it, so you can start your car without it the next time, until it sees the right resistance again, at which point it turns it back on. You will know it is disabled because the "security" light will be lit on the gauge panel.

This might help if you do get all the possible resisors, that way you can temporarily disable it without having to permanently install the resistors into your car, and when you do get a new key, it will then reset itself and go back to normal.

 

I dont know if this helps... but my car was in the shop last week, and the shop lost my keys!!! Anyways, I had to call GM and give them my information(VIN # and other info to ensure that I owned the car.) anyways, the shop picked up the key, and it didnt fit at all. They ended up buying a whole new locking cylinder and they tried to get their money back for the key but GM refused a refund. Anyways, the locksmith shows up to install the new cylinder and they show him the key that doesnt work... he just shaved something down and got the key to fit and now the key works(so I got kinda screwed out of a new cylinder there)... it goes in fine and turns fine as well, but the problem lies in taking it out. It is very hard to remove the key at times, as I have to give it a hard jerk! I fear that Im going to break the key or the cylinder someday...