Since 2010 with Redbull Teaming up with Gran Turismo for the X1, and most recently with the wonderfull book "The Timeless Racer" from Daniel Simon, I've been "trying" to design a custom "Race" car in 3D.
"Trying", because I've never really succeed at it. Since 2010 I've tryed at least 4 different design iteration + an airplane, and I've never been close to a result I really dig. The overall shape always looked good for me, but the final result look always weird and clumsy for the details and smooth surfaces...
Reason for that many failure, 2 big mistake : Jumping too early on the 3D before fixing the 2D blueprint, and using a software that doesn't match my need (and also limited skills, it's too easy to blame only on the tools).
Turn out using polygone modeling is too hard for me regarding product design. So, next time I'll go back to my first 3D Software (Rhino), much more convenient for product in my opinion.
It's always good to try different design process, even when they fail.
(Above, image from Daniel Simon's book "The Timeless Racer")