Wass was still a teenager when he started with BRM in the early 1960s at Bourne in Lincolnshire. He learned the design trade from famous F1 designers Tony Rudd, Len Terry and Tony Southgate - who followed one another at BRM - and studied mechanical engineering in his spare time, gaining the necessary certificates. He stayed with the team until it was liquidated in 1974. He then followed Southgate to Shadow in Northampton and worked with him until 1976 when Tony left to join Team Lotus. Wass took over the design of the Shadow DN8. Southgate returned the following year but at the end of 1977 the two engineers, Jackie Oliver, Alan Rees and others quit Shadow and established the new Arrows F1 team in Bletchley. Wass was the "W" in the Arrows name and he and Southgate produced the early Arrows chassis together - including the FA1 which the British High Court ruled was an illegal copy of the Shadow DN9. Southgate stayed with the team until 1980 and then Wass was left in charge of Arrows design. He produced a string of straightforward but underfunded cars which did moderately well. The team's first composite chassis - the BMW turbo-engined A8 - scored 14 points in 1985, the team's best season to that point.