Saw this in AutoWeek a couple of days ago.

VroomBox

VroomBox utilizes a powerful microprocessor to digitally recreate the sound of 15 different cars and fantasy vehicles, and play them through speakers under the car. It even includes special effects such as screeching tires and turbo blow-off valves that trigger automatically. And you can download more cars and effects from the web. Sounds and effects are controlled from a small faceplate with a backlit display that fits neatly on or under the dash.



I expected one mode where your car keeps saying "That thing got a Hemi?"

 

This has been posted at least 2 times already.