Hi - I have the Eibach springs fitted to mine - I paid similar money at CPR (Car Planet Racing in Warrington) but this included a full 4 wheel alignment.
They also recommended the use of E36 bump stops which I had fitted at the same time.
I didn't however have the 'guide supports with shaved mounts' fitted and these were not recommended at the time.
The car rides superbly and the 4 wheel alignment really sharpened up the OEM 'dull' feel to the steering that the car had before.
The car has been running for over a year I think now, but with no rubbing issues at all - in fact it drives superbly and the ride has not been compromised at all.
thread here: http://www.e90post.com/forums/showth...ght=m3+lowered