I remember hearing on some cars (I think trans ams) that sunroofs are not an option with the bigger engines because they can have so much torque the frame twists too much for the sunroof.
Is there a point this would be true for FDs? Or is there any real downfall of the sunroof other than if you visually dont like it?

 

Im not sure at which HP the frame might be compromised but if you look at the roof on an RX7 with and with out a sunroof they both have a curve in the middle to improve structural integrity, as a side note the new vette also has the same dip in the roof

 

I have a 3rd gen without a roof. It's the most solid 3rd gen that I test drove out of 3 other touring models. I don't know if that's the tire/suspension or actually the roof.

BTW, the aero roof is designed to accelerate the airflow so there's less air turbulance in the tail. It has nothing to do with structural integrity or chasis flex. It's a styling added bonus too.

 

Any hole cut into the middle of a roof will compromise the structural integrity. Why do you think the Z06 only comes in the very ugly coupified version and not the much nicer on the eyes removalble top/hatchback? The amount of flex you may see may be very small (especially on the street), but when you're cornering at racetrack (or AutoX) conditions, it will be felt. That's why Mazda only has R1/R2s without the moonroof...

 

Not a problem on FDs....most of the Japanese supercars have something many US of A cars don't....build quality. I think the C5 is probably the 1st car from GM that is structurally worth a darn. Just my observations from owning some of each.

 

What, did you chop the top off of a FD ????