I have had success with the following at my last 4 track events.
Lowe's Home Improvement Warehouse (and probably other home improvement stores) carries what I believe they call polyethylene repair tape. This tape comes in a 2" width and is much thicker than packing tape and not quite as sticky. I generally use two rolls ($8 worth) and tape behind the rear wheels, the rocker panels, up about 6" on the doors, behind the front wheels and the entire nose up to just past the headlights.
It prevents damage from 'small' rocks, but mostly prevents the black marks that oil and little rubber track goobers leave on the paint. I have left the tape on for as long as 4 days (in 100 deg. heat). It leaves no residue and comes off easily (the warmer the conditions, the easier it comes off).
Every time I use it I find places where it would have been nice to apply some more and do so next time. I thought I would pass this information along to my fellow open trackers.
