BTW and as an afterthought, has anyone looked at the "new" Trans-Am? The team I run with is supporting a car, it's something like $130K ready to win, loud, manual gearbox.....replacement bumpers are $150 or something....easy to go fast but tough to go really fast.....apparently a blast to drive and good racing. That's "visceral"..... then again, watched the WEC Silverstone today, the cars are quiet, composed (LMP1, LMP2, even the GTE's with exception of the RSR and Aston). Those are the fasted race cars around (other than F1) and, while no power windows, refinement = speed.
I know this is an old post, but I've been working on a TA2 Mustang the last few months, and they are a great platform. 351W with a 5 speed. Can't go wrong there. Also, to add to the GT4 discussion, Mercedes has released the AMG GT4 and I will be working with a team campaigning them in the IMSA Conti series for 2018. Can't wait to get to Daytona, its gonna be a great field with some awesome racing hopefully. https://www.mercedes-benz.com/en/mercedes-benz/vehicles/passenger-cars/amg-gt/mercedes-amg-gt4-a-new-class-of-performance/