For more than 40 years Aumonier was a prominent figure in the management of motor sport in Great Britain, including long periods as both Secretary to the Meeting of the British Grand Prix and President of the FIA Sports Car Commission.
He first joined the BRDC as press officer at Silverstone in the late 1960s and was soon appointed assistant to the Club Secretary, a position he himself would take up in 1979. Pierre would become well known throughout the motor sport industry, and in his later capacity as a Director of Silverstone his vast experience and knowledge – he also acted as a race steward at Spa-Francorchamps, Nurburgring, Hockenheim, Kassel Kalden and other European circuits – would influence many senior Clerks of the Course.
It was as Director of the Meeting at the 1994 British Grand Prix that his license was controversially suspended for a year after the stewards failed to disqualify Michael Schumacher for ignoring the black flag. Elsewhere, Pierre served on the committee of the RAC Motor Sports Association and the organizing committees of the European Saloon Car Championship, the Formula Two Alliance and the Trans-Europe Trophy, while away from the sport he was until his death Administrator of the Northampton Festival Opera.