I don't think this counts, because I wound up sleeping for about 5 hours in the back area of my old Scout, but that and a 1 hour turnaround were the only stops (other than fuel) that I made in an 18 hour run to L.A. and back at 55mph (towing a vehicle there and towing another vehicle back).
I think I have driven 10 hours in one shot (only stopping for fuel/food/nature calls), but for any longer of a period, I try to get some sleep.
