Also, i may be wrong, but i thought the 300SD was only made till '85? if thats true you may be looking at a 300SDL, which is a little longer. Again, i may be wrong. I also remembered some of the "creature comforts" my car does not have that the 91 300se does. The 300se has memory seats(passenger and driver) with power headrest, a digital outside temp display, a tilting sunroof, an extra coin holder, and i believe it has a one-touch down drivers window, but i'm not sure on that one. Again, hope this helps
Ryan