This is an interesting find. This detailed R/C race car was made by Nikko America in the 1990s. It was likely found at Radio Shack and other stores that had remote cars. As you can see, it's covered in decals and details, such as shoe pictures on the tires, and Sonic from every angle. It uses 4 AA for the car and 1 9v for the remote.

The car is not that large, and the remote looks to be control-pad inspired. The fin says "Attitude", and that thing on/above the back is a weight which enables it to do tricks, but it falls off easily. 

• Detail photo by Brangeta Detail photo by Brangeta
• Detail photo by Brangeta Detail photo by Brangeta
• Detail photo by Brangeta Detail photo by Brangeta
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With these photos, you can see there was a red accented variation on this car/control set. *colors may indicate Mhz, this one at 27 Mhz. The car is a short/squished version of the Mitsubishi 3000GT, and it is at 1/26 scale. It's sort of odd how the different 'views' of Sonic all have him at different sizes. Look at the windshield, he's so huge there, while one 'side' has him far smaller than the other. It's a quality little car though, with headlights that really light.