I think I see the problem. The tarp goes UNDER the car if you want it to float. In the military years ago we used the method of driving a Land Rover onto a tarp, wraping it up, and floating the bundle across deep rivers etc. Being a fair shot I sometimes had the job of sitting on top with a loaded SLR (FN-FAL) and watching for crocks and sharks. Other diggers had to wade out with tarp to mid chest deep while vehicle was driven in. I found that any sudden increase in my apparent interest, such as raising a little and half lifting the rifle would induce extreeme nervousnouis in those who were wet. God will probably punish me for that one day.