GRX was an automotive brand founded around 1993 by Tommy Mouzes in Kenosha, Wisconsin. The brand is primarily known for its development of the GRX Interceptor, a distinctive mid-engined prototype that showcased innovative design and engineering.

The GRX Interceptor featured a unique combination of Chevrolet sedan suspension and a V8 engine, which contributed to its performance capabilities. Mouzes envisioned the vehicle as a potential star in a film, reflecting a blend of automotive engineering and cinematic ambition.

Despite its ambitious design and purpose, the GRX Interceptor was later offered for sale at a price of $1.8 million, highlighting its status as a specialized prototype rather than a mass-produced vehicle. The brand's activities and the fate of the Interceptor remain a niche aspect of automotive history.