Hi,
There is another way of tackling this problem.
Eveyone in the club has a ranking based on the seeding system in the rule book. It could be a good idea to award prizes based on the "F" grading of drivers rather than just dividing it up into Modified and Clubman.
We could still maintain prizes for top 3 in Modified and Clubman, but then award extra prizes for best F2, F3, F4, F5 (we've no F1 drivers in the club at the moment

) . Top three in mod and club would be not included so that nobody goes away with two prizes.
Effectively, this means that RTR drivers could race for the F5 prize (making the assumption that RTR racers are all newcomers and F5) without having to be competitive at the top of the Clubman Class.