Born in Dublin, Smith won Ireland's Fiat Punto championship in 1998, winning 12 times, before trying single-seaters for the next year.

By this time he had already made his BTCC debut in a one-off at Mondello Park, and he tested a VX Racing Vauxhall Astra in early 2005.

Gavin was 10th overall in 2005, although the fact that he was retained for 2006, while Colin Turkington was fired after finishing 6th, tells its own story.

In 2006, Smith improved to 8th overall, but lost his drive for 2007 when VX Racing downsized to a two-car team due to the pressures of preparing new-specification Vauxhall Vectras.

With 3 rounds of the 2007 season to go, it was announced that Smith would join GR Asia in alongside Adam Jones, driving a 2007 spec SEAT León.