Sorry for gatecrashing, however why dont you introduce a deposit scheme, especially for the packing away, and they pay have to pay a additional £1.00 or £2.00 and once the track is cleared away you get that money back, however if you leave early the money is kept by the club. Ive seen this work in a few clubs before, and seemed to be very successful.
However you have to understand and take into consideration you may get drivers who have travelled a far distance, and want to get off as soon as possible.
Just an idea
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