A leading driver in his native France, Thomas traveled to the United States to compete in the Indianapolis 500 on four occasions.

[4] Laminated spring steel steering wheels were manufactured in the inter-war period engraved with Thomas' portrait and signature and were used particularly on Delage motorcars, but also by racing driver Jean Chassagne on his winning 1922 TT Sunbeam.

[5] On 6 July 1924 at Arpajon, France, Thomas set a new world land speed record when he drove a Delage at 143.31 mph (230.64 km/h).

In Milan Italy in October 1910 Thomas was involved in the world's first mid-air collision when his Antoinette monoplane fell onto the Farman biplane of Scottish aviator Captain Bertram Dickson.

Thomas miraculously was not seriously injured but Dickson suffered internal injuries and never fully recovered, eventually dying in 1913.