KDU 497N was the first TR7 rally car to be built and was used as the development vehicle for the programme, the first test of which was on 4th March 1976. Although the TR7 was not yet available to buy with the 16 valve Sprint engine, this power plant was homologated from the beginning and was used for nearly two years before the V8 powered cars appeared in April 1978. The TR7 rally programmes third test session, held at Chobham, was also used as a publicity opportunity with the press being given rides in KDU 497N.