I have a set of Eibach Pro kit springs off my 95 M3, like new, about 5k on them, will fit 96-99 also but will need to swap the strut hats (only a few bucks at the dealer) $200 shipped. Still have the box and brochure that came in the box.

how much is this supposed to drop the car?

I beleive is 1.1 front and .8 rear