David,
I use Thetford's wash and wax on the coach. When I first bought the coach I applied 2 layers of Meguiars Gold Class paste wax, and for the past 2 years I have used the Thetford's. Here is a link
http://www.thetford.com/rvcare_products.cfm#washwax
As far as the amount goes, the coach usually gets washed once a month. This year I have not been able to get the amount of cleaning on the coach as I would like, hopefully things will change as the summer continues. Every third month I try to get a layer of Protect All on the coach as well.
http://www.protectall.com/pawaxlg.htm
And to top it all off, I use Aerospace 303 on the decals a few times a year.
http://www.303products.com/tech/inde...TOKEN=19135823
This seems to help keep the decals from peeling,cracking and fading from the sun.