The BMW M Coupe may be one of the few cars where you may not want a sunroof. Sunroofs came standard on the M Coupe with the option being a “sunroof-delete”. Very few dealers ordering for their lots wanted to de-content their cars, so very few have this rare “option”. It’s been reported that only 16% of coupes are sunroof-deletes (452 of 2858 to be exact).
Why Wouldn’t I?
First of all rarity. M Coupes are rare cars to begin with, but if you’re one of the few and proud to own a sunroof-delete, you truly have something special.
Second, the M Coupe was designed to be raced. Having a heavy glass panel on your roof raises the car’s center of gravity and takes away some structural rigidity. So if you plan to track or autocross your coupe or if you want your coupe to be more in tune with the intentions of it’s original design, go sunroof-delete.
Third, the sunroof of the M Coupe only tilts, it does not open. It seems almost an afterthought by the designer (see #2 above).
Fourth, the roof of a sunroof-delete coupe looks more clean.
Why Would I?
First, you don't like paying more for less. There seems to be a price premium on sunroof-delete coupes, and if not in price, they seem to sell faster. Many people don’t like paying more to not have something they typically have to pay more to have.
Second, you like the open-air feeling in the interior.
Third, you like fitting in.
Last, there is actually a little more headroom, especially when the sunroof is tilted. This could be critical for taller people who need to fit a helmet at the track. (thanks Chuck)
Personally, I think I’m neutral on the issue. I don’t think it’s a make it or break it issue in my own car purchase. I typically love having sunroofs in my cars. The reasons above are what evens things out. There’s something about having a car in a configuration you know there are less than 5 of.