I checked the link you included but wasn't sure what to look for. Can you give me a brief comment re "structural" issues?
Please note I am once again beginning as a BMW driver, and never had driven an M, so perhaps I may not reach the point where these difficulties arise. My dealer, a fair guy I think, suggested that buying a cabriolet for the track is NOT a good idea but someone at my level of driving I probably wouldn't notice too many of the limitations. To be honest, it's either a cabriolet (only option here) or waiting for about 2 years for the "2008" M3.
What are your thoughts? Are the structural limitations such that I should not sign the papers?
Obviously I respect your thoughts, b/c the dealer has another motive ($ to feel his family).