I recently bought a used Audi TT Roadster (only 21K miles).  The car looks and runs like new, but when you first start out there is a funny noise after letting off the brake.  It sounds a bit like an electric motor reving up for about 3 or 4 seconds.  This problem goes away after about 15+ minutes but returns each time I start the car.  It doesn’t interfere with the operation of the car, but it is annoying.  What could it be???
 Thanks,
 John C. Snider
 Kissimmee, FL