my girlfriend was in an accident she was rear-ended and pushed under a van in front of her and her airbags did not go off. i was wondering where the airbag sensors are(a diagram would be nice). thanks

The airbag front impact sensor is in the center of the front of the car directly under the hood latch and the control unit is under the console between the two front seat. In order for your airbags to go off, they both need to feel an impact and a change of speed of @ 30 mph simultaneously.

Here is a website that has lots of resource pages to give you all the information you need to understand the system
http://www.airbagsolutions.com