Re: FPV - interior stink !
I might be way off base here......but......when was the last time you had a bath ?? Try having a bath/shower and then go for a drive, see if that "smell" still lingers. Can your passengers smell anything ?? if not they just may be too polite, get a good mate to go for a spin with you, if it's you he will let you know.
NOTE: above comments in jest.
When you crank it up, the LS1 feels like a rottweiler with rabies and distemper on a short thin leash that's constantly being poked with a sharp stick.