I have a 1990 vert. I have what looks like OEM black emblems on the front of the bumpers, not the molded "mazda" I have seen in most rx7 bumpers for my year. I was wondering what year bumper I have on my car.

 

That may be an S4 bumper from 1986-1988. Look at your molding on the fenders, doors, and rear bumper. Does it match the lines on the front bumper? It should make a complete stripe around the car.

Do you have pictures?

 

on s4 the bottom lip of the bumper is straight across, while the s5 i dips in a little.