[W9WLS]

On a similar installation for a friend, we used a piece of old RG-8 coax with the center and shield tied together at both ends from the mount to the frame of the camper, tied to the frame with a long stainless bolt and electrical clamp.

Next, we made a "ground Radial" system with a jumper cable clamp and several (10) runs of #14 thnn (green) insulated wire at assorted lengths.

When he sets up, he just clamps the radial system to the bolt and spreads it out as best as he can on top of the ground (depends on where he is set up) and starts making contacts.

Between the frame ground and the radial system he doe's very well.