"I think the year I won it there was still a decent field but there were limited number of people that could win it," Murphy explained. "It was a combined field - Formula Brabham and Formula Atlantic cars and I was definitely in one of the faster cars that was capable of winning it.
"It struggled for quite a while after that to have the significance it deserved. We really didn't have a class to tag the Grand Prix to for a while there but in the last few years TRS is a worthy class to be running for the Grand Prix."
Having run as a Formula Ford race for a few years in the early 2000s, the emergence of the Toyota Racing Series in 2006 saw the return of modern style cars and international drivers.
The TRS organisers have focused on getting young stars on the way up and that seems to have worked with the series now one of the leading categories staged at this time of year.
"I think it is a fantastic series that has been put together," Murphy said.
"There are a lot of young international drivers coming over. Young drivers with big futures and some of those guys that have been here have gone on to bigger and better things including Formula 1."
Recent winners Earl Bamber, Mitch Evans, Nick Cassidy and Lance Stroll have all gone on to compete in major world championships while 2016 winner Lando Norris is expected to crack Formula 1 within the next 12 months.
On Sunday afternoon another young driver will etch his name on to the famous trophy.