I read about ceramic window film in another thread antd went searching to find out what and how it is and works,Here is a video I found looks like interesting stuff
http://www.youtube.com/watch?v=8lkLTsRA8I4
I had that installed on a previous auto and it worked quite well in the greater Houston sun/heat.
The only caution for motorhomes is that it was not recommended for double pane windows. Something about the reflected heat from the inner pane building up too much in the gap between the two glass panes.
The PO of our coach had some kind of heat-reflecting film installed on the inside of windshield. Sorry - don't know the brand. Since I have not driven without it, I can't personally vouch for its value, but the PO said it made a BIG difference especially when driving west in the afternoon.
One drawback I discovered: if I wear polarized sun glasses the combination of the glasses and the film produce a "rainbow" effect that is very distracting. I solved that by switching to non-polarized glasses. Don't know if all films of this type would have that problem.
3M Crystalline Automotive Window Film (http://solutions.3m.com/wps/portal/3M/en_US/Window_Film/Solutions/Markets-Products/Automotive/Crystalline-Automotive-Films/?&WT.term=+3m%20+crystalline%20+films&WT.source=google&WT.campaign=Auto%203M%20Brand&WT.medium=cpc&WT.content=text&WT.srch=1&WT.mc_id=3MAutoFilms_Paid_Search&cshift_ck=2082AB33-7F0C-4D04-8E1E-0D7F6D7CD4CEcsKocijpZp)
I believe this is the best in the industry right now. It is expensive and must be installed by a very experienced installer. It must be heated at a very high temperature to be install it properly, i think 600 degrees heat. We had it installed on our previous FT windshields and driver & passenger side windows. Before and after effect at 90+ Texas heat was very significant. I can't wait to get it installed on our new to us 03 FT.
New window film (was What did you do to your coach today) (http://www.foreforums.com/index.php?topic=15484.0)