We have recently bought a 1998 Mercury Tracer wagon and I was wondering if there is any way of knowing if the safety equipment (airbags, seatbelts, the built in child safety seat) are still functional. The car has never been in an accident and there are no problems readily visible. The seatbelts work fine as far as we can tell. We did not try out the child safety seat; our 12 month old son rides rearfacing in an Evenflo Triumph 65 as he did in the vehicle prior to this. Is it safe to assume that if no problem is discernible no problem exists? How can we know?