Looking at a 2003 Cobra vert at a local dealership...it is bone stock down to the factory air box and ford mufflers...has 91k miles.....question is while listening to the engine, it is making a whining noise on decel after revving it up..doesnt sound like a turbo waste gate... almost like a pulley whining after letting off....does it with AC on and off...dealership says it is the supercharger...? any input?..we are going to test drive it again this afternoon.