I have been using a clay bar on cars/pickups for years. We get tar, lots of tree sap and bird poo on the vehicles. Never tried the bar on the RV. The bugs and stuff come off while washing with a brush. I wax the RV 1 time a year or use 303. Should be doing it more, just do not have the time.
2013 24RKSWE (27ft TT) Cougar 1/2 ton series
2013 Ford F350 4x4 CC 6.7 engine, 8 ft bed 3.55 rear end lariat package
Retired from Oregon State Police in 2011 than worked another 9.5 years as a small town traffic cop:
As of 05-2020, I am all done with 39 years total police work. No more uniforms for me.