The 100 hp was a Grand Prix racing car built by Austin in 1907. In the winter of 1907/08 Austin built four cars to enter in the 1908 French Grand Prix. Theser were two shaft and two chain driven cars. Both of the shaft driven cars were crashed during practice. The parts from these were used to make a third chain driven car.
All three cars started the race driven by Warwick Wright, Dario Resta, and J.T.C. Moore-Brabazon (later Lord Brabazon of Tara who went on to hold the first ever British pilots licence). Warwick Wright was forced to retire with a seized engine, while the cars of Moore-Brabazon and Dario Resta finished 18th and 19th respectively and were also the highest place British cars.
The cars shared many parts with the then current Austin 60 hp touring car and were no match for the continental racers. Afterwards the cars were sold on as fast tourers.
The Moore-Brabazon car is the only survivor of the team and is on show at the Heritage Motor Museum at Gaydon, England.