first off your car doesnt qualify as a lemon, that is only new cars with the same issue happening, etc first time srs light, 3 weeks later srs light again, 2 weeks later srs light again. your car is too old to qualify. there are no recalls on this just bulletins.
now a bad cylinder head isnt going to neccessarily cause the car to stall. on the c230's the issue with the cylinder heads had to do with check engine lights caused by worn valve seats causing misfires. now have you taken it back to have them check the car?????