To the OP the E36 is likely one of the most fun cars that someone could possibly put together. All the homework is done, it will fit all the tire that you want and there are suspension options out there galore. You can even pick up almost everything you need, right now to have a car as fast as you need it to be to win the ARRC in the bimmerforums classifieds at nearly 50% off. Things that aren't there are front brake pads and tires.

The chassis reinforcements are these: http://www.turnermotorsport.com/html..._ID=4111225649

If I had a week I could likely find the Roundel from over 10 years ago that had a statement regarding this from BMW.

I have no dog in this hunt. I am a BMW guy but when I was ready to buy the ex KVS ITS 325 all the weight/restrictor/dyno unrest was happening so I went another direction.

If I were to consider a car for ITR I would not consider any option other than the BMWs. No need to make life that difficult to go slower.