Vroominator engine sound generatorEnlarge Photo
Your wishes have just been answered, and for only $40. What you need is the Vroominator!
As you can imagine, $40 won't get you the performance of a proper sports car, but it'll get you some of the noise. Plug the device into your car's DC adapter and it syncs with the alternator signal to provide your car with a rowdy soundtrack, albeit one that can only be heard inside the car.
So, if you've just ordered a new Chevy Cruze but aren't impressed with the four-cylinder soundtrack, get yourself a Vroominator and turn it into a Camaro. Aurally, at least.
What it can't do is give you a sporty soundtrack to a hybrid or electric vehicle, but if you own one of those you probably appreciate the silent life anyway...