Pretty cool video @BearChow I hadn't seen that one before. I've seen the aircraft cable looking cables before on the front of people's rides....is that to prevent branches from intruding?
I couldn't tell you without a closer look, but on an actual aircraft that's a radio antenna, so it could be for a CB radio. Could also be tie-down cables for that roof rack, or a few extra feet of winch cable.
EDIT: Looking at them, those cables look very much like the radio antennae I've seen on personal aircraft. My guess would be something of that sort.