>>>I believe the answer is the door lock actuator.>>>

That is correct. As for the dealership not knowing what you were talking about, that's rediculous on their part... it's been a common problem for a long time. The actuators went out in the rear doors on my 96 at 40,000 miles. When I would press the lock button, the front doors would lock but the rears would make the 'whining/buzzing' noise you described.

>>>>door lock motors make that loud spinning noise. ABS units leak (expensive fix) front motor mount breaks.>>>>

Forgot about the motor mounts. I had to replace the rear mount on the 96 at about 50k miles. I never did have a problem with the ABS system, but it was also a common problem area on both the 4th and 5th gens.

I also forgot about the oil seals, call HOA and give them your VIN# to find out of if the vehicle was repaired via the recall. The oil seals on the F22 engines had a tendency to 'pop' out and drain all of the oil instantly. There is a retainer kit that can be installed that prevents the seal from failing.

96-97s (and 95s if it's a V6) are under an extended 14 year/150k mile emissions warranty that covers quite a bit of stuff. Between 75k and 150k, you are entitled to one free tune-up and oil change. The warranty covers most things that would trigger the SES light and also covers the SES light diagnostics. Your local dealership can give you a print out of everything that is covered under this warranty.