What a pile of BiaS. If you want the Carrera GT to hold a record, why not just tailor the class specifically for it? Go on, just make something up.
The CGT is marketed as a very focused, carbon fiber, limited-production car. It's not a mass produced car like a 911. FIA production car standards require 5000/year, which seems pretty reasonable.
Maybe you should expend your energies on asking how fast the CGT would be if it didn't weigh >3000 lbs. Oh, but then the "wealthy older gentleman" demographic wouldn't buy them.