My '82 weighs 2963lbs (and that is with a slushbox). Doesn't the 535i weigh around 3400lbs ? Four hundred is a pretty sizable difference, like having two or three extra passengers and you definitely notice that. I think a 533i owner here said that those are around 3100lbs. I'd get one of those and take some junk out of the front, then you'd match a stock 528e with weight. Plus the 533i has an additional coolness factor by being older and fewer