303 Multi Surface Cleaner and 303 Aerospace Protectant are all you will need for awnings, toppers, slide out gaskets, rubber trim, etc
Don't waste money on RV specific brands like Camco and Thetford from Wally World
This is what hard core full time RVers use
There may be better looking tire/rubber dressings but what you should be after is long term UV protection for all that stuff and that is where 303 excels
Get yourself a quality extendible pole setup with a brush head for awnings and several microfiber heads for the paintwork unless you like moving a ladder 20 times per wash