· Horlicks Hero
I used to do this at my kids' school. We charged €1 for 2mins. Fastest lap of the day won a prize. Prizes were slot related such as cars or a small set. The old Start set with a pair of Audi TTs in it can be had quite cheaply. If you talk sweetly enough to your local hobby shop, they may even chip in a prize for you if you're willing to put up a sign or something thanking them for their generous donation. Hey, it never hurts to ask.