 The car's bodywork, featuring swooping fenders and an aircraft-like tail, infused by the company's knowledge of aircraft aerodynamics, was mainly designed by Jaap Tjaarda van Sterkenburg, brother of John Tjaarda and uncle of Tom Tjaarda, both also car designers.On November 27, 1920 the first Spyker 30/40HP C4 was completed, sporting a 6-cylinder Maybach engine of .The car waws nicknamed "Tenax" (latin for "tenacious") and improved the long-distance endurance record, held since 1907 by the Rolls-Royce Silver Ghost by some 6,000 km.