SR4 chassis number 23 originally came with a Kawasaki 1200CC engine. In 2004 Radical used this car as a test car and installed a 1500cc Hayabusa based engine. At the time it had license plate “SR04 RAD). It was rumored that many engines were tested before the proper combination was found. The car was then sold in Belgium to “Domec”. The next owner was from Luxembourg who used it until around 2012 for track days. The next owner was a competition car salesman who used it for track days. Then the car went to an owner in Belgium who used it for hill climbs and had a few victories. In October 2021 the car was owned by Christoph Figue and it was located in Belgium. Christoph plans to use the car for races in Belgium and in other parts of Europe.