Originally Posted by bigjae1976
Would the M3 GTS wing be somewhat decent in providing some rear down force?
Not really. It is way too small. If you're going to go for a wing do it right, APR or Bimmerworld/Brooks. I'd say the GTS wing provides "some" downforce, but it would be a fraction of what a real race wing can provide. Your best low-cost bet is APR.
I don't have a wing on my E92 yet, but if/when I do it is going to be for sure either Bimmerworld or Brooks. Proven aerofoil designs and sturdy mounts.