yes, his m3's are all build to latest dtm spec...!! the trailing arms for a 318i and the 318is are different! i think where the brake calipers are and some other angles... i know that the 325 (not ix), 318is, m3, are the same z3 and 318ti fit too, there are only some more reinforcement. all other trailing arms from other cars are different...! look at realoem!
by the way.. he owns a douzen of m3's.. evo's and other bmw racing cars!! for example the tictac m3 (you can google that..)the car is now totally green without white points but the parts on that car are... AMAZING!!INCREDIBLE...