Any wax with carnuba would be good, as it has the highest resistance against heat melt down. Most waxes get "soft" in the summer sun, and dirt/dust settles on this waxed surface. When the surface cools, the dirt and dust can get trapped in the wax, dulling the shine, and requiring a clay bar to remove.
2015 Jayco Jay Featherlight SLX16XRB (TT)
2007 Ford F150 Tow Vehicle (TV)