I have 2 local dealers who each have good condition M5's for sale. One is a 1991 model while the other is a 1993 version. Aside from the usual issues such as mileage, availablility of service records, general condition and price, is there any major difference between the model years which should influence my decision? I am going to drive both, but have little frame of reference as I have never driven a BMW before, much less an M5.