Work started on the all-conquering MK III in 1994. It all started when Rob Dyson asked the Rileys to improve on his Spice/Ferrari WSC. This initial step into WSC gave Bob and Bill the inspiration to design their own car for the growing IMSA WSC series. The MK III is considered to be one of the most successful sports cars of all time. The car has over 60 race wins, with derivatives of the car still in competition to this day.
Created as a reaction to the collapse of the IMSA GTP class, WSC was designed to make prototype sports car competition affordable for "privateer" entrants. The Riley's designed the car based on the principles of building a fast, low maintenance, easily affordable race car. The MK III debuted in the Rolex 24 at Daytona in February 1995, with Dyson Racing. Dyson won 5 races the first year, and was in contention for a win in almost all.
In 1996 the factory team was started and they won in their inaugural race, the Rolex 24 at Daytona. The team followed up the initial win with a stellar season including a win at Sebring and the championship at years end. The Dyson team followed up the Riley Daytona win in 1996, with their own in 1997. The Dyson team won four of the eight rounds of the IMSA series and the team and driver Butch Leitzinger, clinched the championship.
In 1998, six MK IIIs took the green at Daytona, but the Ferrari 333SP scored its first and only 24-hour win. Throughout the season Dyson, Jim Matthews, Intersport, Transatlantic Racing, Support Net Racing, and BMW Team Rafanelli competed with MK III's. Despite the increased competition, the Dyson Team remained dominant, winning the Team and Driver's Championships.
A WSC series known as the ISRS (International Sports Racing Series) began in 1998, and grew into the FIA Sports Car Championship by 2001. Bill Riley established a European division in 1998 to service the growing number of customers in that series. As many as four MK IIIs started ISRS events that year, fielded by Solution F, Target 24, and BMW Team Rafanelli.
After the Rafanelli car secured the MK III's first European pole in the 5th of eight rounds, the Solution F car, piloted by Gary Formato and Jerome Pollicand, won the final race of the year at Kylami in South Africa.
The MK IIIc is the latest generation of the venerable sportscar. The car was designed and production began on cars in 2001 for Dyson Racing and Robinson Racing. The car competed in Le Mans as late as 2003 with Jim Matthews. The success of the car exceeded most expectations of what a privateer team could accomplish at the world's biggest sportscar race.