I watched the episode last night and found identifying the two cars somewhat difficult. The one Grant controlled was obviously a 95 but had a wide grille and a hood for a narrow grille car. I am assuming one of the cars was a 530 or 540, as they taped over the first two numbers, leaving only the '0', but a top speed of 105 sounds a bit low for a 540 (I happen to know it is about 20 MPH faster).
Now, it is my understanding that the e34 is a 50/50 weight distributed car. It must not be true, or I misread somewhere, because they filled the trunk of the e34 that took a trip for 4000 feet with cinder blocks. The result was quite impressive as the car basically fell horizontally.