Date registered: Jul 2005
Vehicle: 99 ML430, 00 ML320, 05 E500 4matic Wagon
Mentioned: 22 Post(s)
Quoted: 1140 Post(s)
Which airbag fired off?
Was the car purchased from a Mercedes Benz dealer as real MB CPO car?
If was not purchased from a genuine MB dealer then all bets are off. If it was from an MB dealer as CPO car then have it hauled back to them and start a serious discussion with them. Even it means they have to replace the car or refund the price due to having no confidence in the car's safety.
Lots of used car lots and dealers of other brands "certify" a used car, but it is not the same as an MB dealer selling a CPO car.
It is scary to have an airbag go off in accident let alone all by itself while driving. Were you driving the car it did it happen while it was parked?
Either way from whoever you bought it from it warrants some digging into. There are places to file the issue in both your state and at the Federal level.
I have been here a long time and this is the first time I have heard of a spontaneous airbag deployment with a car as new as a 2013.