I seen some that guys used in their jeeps and pickups back in the 90's down in Mexico. They were 15'-20' towers. They had someone drive while one guys sat in the top. They had to guy them back to the front bumper and back bumper in 4 places. They did have a pucker factor up that high for sure.
yeah this is not for driving while up - just pull up in a sendero, raise it, and see over the brush