Why few 135Is at track events

[1996 328ti]

Would the discussion in this thread vary significantly for the 335? I am under the belief (please advise if you think its a mistaken belief) that the 335 is mechanically identical, and only slightly different in the body, to the 135.

Down the road I could see tracking my 335, but I also see that some (probably significant) expense would be involved in preparing this vehicle for track. That's part of why I am not tracking the 335 at this time.

From what I understand, suspension from a 335 can bolt up into a 135.