Originally Posted by e36jakeo
I instruct for four different track clubs. I race in time trials. I won my class last year in an E36 M3 -- with a roof.
Formula 1 cars are designed without a roof, as are Boxsters, S2000s, etc. Thus they are designed from the ground up to be stiff and relatively light (3000 lbs or so). It allows them to handle well.
An M3 is designed as a 4-seat coupe. With the E92 M3, it even has a CF roof to keep it light and with a lower center of gravity. Huge strides are taken to make it have a stiff chassis that does not flex when presented with huge loads in high G corners. This allows the suspension to do its job properly and allows the car to grip the pavement and remain balanced.
By hacking off the roof to create the M3 Convertible additional chassis strengthening is necessary just to make it half as stiff as the coupe. This, plus the electric mechanism that raises and lowers the top, plus the metal top itself, weigh at least 400-500 lbs. For reference the 335i Vert weighs 400 lbs more than the 335i coupe (which has a metal roof and sunroof). I'll bet the M3 Vert will weigh over 4000 lbs.
I am NOT against convertibles (I have an S2000). I too love putting the top down and running through the No Cal twisties. But to take a car that costs a lot of money because of how much engineering went into making it stiff, strong, relatively light, and fast, and then chopping off the roof, thus eliminating so much of what was good about it makes no sense.
But I have the mindset of a racer, not someone who just wants to drive a cool looking, V8 powered, heavy 4-seat convertible. I'd rather get a used S2K for $15K for when you want to do the top-down thing and then get the real M3 -- the coupe (or sedan).
OK, enough mudslinging. Just opinions, guys!
An M3 is not designed to be a coupe, an M3 is designed to be a high-performance variant of the regular 3-series line. An M3 coupe is no more a pure M3 than the sedan or convertible, so I don't know what you mean when you say a "real M3". Your argument sounds like BMW engineered the M3 only as a coupe and then tried to add the M3 goodies to other variants. For some reason, I tend to believe that BMW took a 3-series convertible and upgraded it with all the M3 hardware and tuned it specific for the chassis. So while the convertible may not perform as well as the coupe, it's by no means a "compromise". And besides, why does it matter that someone else wants an M3 convertible.
Trying to argue which is better is pointless because people will buy what they want to buy. I would personally opt for the sedan, but that's just me. If I see an M3 convertible rolling down the street, great, I'm sure he's having a great time. I wouldn't call him a poser.