I've never done this, but I've read that the SAR teams like it if you step on a piece of tin foil and leave the resultant footprint visible in your car to make yourself easier to track.
I can't speak for them but this is apparently so. It is one of the things they teach in the Hug A Tree and Survive program. I am currently looking for someone in SAR in the Eastern Kentucky area who is familiar with the program and can teach it at our cub scout roundtable meeting for june.
BTW, nice pics HJ. That is some beautiful country.