I would take the car to the dealer for inspection and certification. It may even still be under warranty. I have learned that airbags have to be inspected every so often and certified.

I can only sumise it was not hit hard enough. When we were hit head on by an accelerating car much smaller than ours. His car was a right off and the Airbags did deploy, Our car just had front end damage and neither Air bag deployed. It was a much larger and newer model .

Probably not hit with enough force and/or from a direction that the airbag will not deploy. May have somewhat "missed" the sensors.

Vehicles use acceleration sensors (detect the 'g' force) and will not deploy the airbag unless the vector of the impact would justify it. The airbags are checked everytime you start your car, if they are malfuntioning the airbag light will stay on.

If you were hit on the side, then deploying the front airbags would not help prevent/reduce injuries to the occupants. Is your car equipped with side and/or curtain airbags?

Did you buy your car new Ed or was it used? It might have already been in an accident. Sometimes such cars' airbags don't deploy. Or maybe you have a lemon. :(

The air bags have sensors that need to read and meet certain levels for the bags to go off. Front impacts will usually deploy the bags. side and offset sometimes will not.

After reading all the answers I agree with Old School. The air bag system did just what it was supposed to do. The Passenger Presence System determined there was nobody on the side of the impact and intentionally didn't deploy the air bags on that side. This is done to save the cost of replacing the modules in less severe crashes where the vehicle is not totaled. The air bag modules run 600-1000 USD each. If your car was not totaled you (or your insurance company) would be happy they had not deployed.

Ed I did my research and here is what I found. I can send you any and all of this if you would like, just drop me an email (address is in my profile) and I can get you all the supporting documents. I still have some questions, I will ask around and try to get some answers from work. DISCLAMER: This is just a guy talking to another guy. I work for GM but this is in no way reflects GM's opinion. So.. From the 2007 Saturn Ion manual under "Airbag System" "Your vehicle MAY (I added the caps) have the following airbags: A roof-mounted side impact airbag for the driver and passenger directly behind the driver. A roof-mounted side impact airbag for the right front passenger and the person seated directly behind that passenger. If your vehicle has roof-mounted side impact airbags, the word AIRBAG will appear on the airbag covering on the garnish trim near the ceiling and the side windows." Translation.. The side impact airbags are an option. Not to insult you but do you know for sure the vehicle had them? If you look at the seventh digit of the VIN it will tell you. If it is a 1 then it only had front air bags. From 2007 ION manual under "When should an air bag inflate". "The driver's and right front passenger's frontal airbags are designed to inflate in moderate to severe frontal or near-frontal crashes." Translation.. Side impact = No front air bag. Also from the manual under "Passenger Sensing System" "The passenger sensing system is designed to turn off the right front passenger's frontal airbag if: The right front passenger seat is unoccupied. The system determines that an infant is present in a rear-facing infant seat. The system determines that a small child is present in a forward-facing child restraint. The system determines that a small child is present in a booster seat. A right front passenger takes his/her weight off of the seat for a period of time. The right front passenger seat is occupied by a smaller person, such as a child who has outgrown child restraints. There is a critical problem with the airbag system or the passenger sensing system." Translation.. No passenger = No Front Air Bag. Now here is where I need more info and I will try to find it. If I look at other manuals of other vehicles (My 2008 Saturn Astra for example) It also says.. "The passenger sensing system is designed to turn off the right front passenger's frontal airbag and seat-mounted side impact airbag if:" (and has the same list as above) Translation No Passenger = No front OR SIDE air bag. I believe your Ion is supposed to work the same way but because the side air bags are optional the documentation in the owners manual left that part out. That what I am going to try to find out. The passenger sensing system turns off the bags if it thinks there might be a small child or a child safety seat in the front seat. You are not supposed to do that but people do so they try to detect it prevent what is known to happen when small kida and air bags mix.

Probably a faulty airbag sensor that caused them not to deploy. If the car was still under manufacturer's warranty then you may be able to claim some compensation depending on what your warranty stipulates.