Probably nothing will be totally safe on the rubber roof but then who really sees that roof. For the other surfaces, prevention first works best. A good wax/polish then a constant watch and removal then rewax the area - both RV and truck.
Many 'love' a product called Rejex (
http://rejex.com/) though my try with it didn't end well as it smeared but may also have been my fault for not doing a thorough enough cleaning first.