Tony Southgate modified the design of the Shadow DN1 that had raced the first part of the 1974 season and studied a wider, stiffer and better aerodynamic car, the DN3. Equipped with the usual Ford Cosworth V8, the DN3 sometimes showed a certain competitiveness, especially with the fixed driver Jarier, while driving the second car alternated with other drivers. For the first races of the 1975 season, a DN3B version was used, which already had some parts destined for the new DN5. In addition to Jarier, Tom Pryce, Brian Redman, Peter Revson and Bertil Roos also drove the DN3 / DN3B.