I sympathise, like you we tow a caravan with a Toyota Hi-Ace & the BMW K1100 or Commando in the back. We used to camp on the bike (not literally) but SWMBO's arthritis precludes getting her leg over with the panniers on. But fine without.
The assumption that everyone towing with a van is a diddycoy bugs me too. If you want to really pi55 someone off, drive into a Caravan Club Site.
I've been shoved in a field behind the site. Been told I can pitch the caravan & park off site. Refused entry to Stratford on Avon Racecourse, even though horseboxes were there. Went a mile down the road to a site behind a mobile home village, where the site owner was surprised to hear of such discrimination.
FFS Don't get a German living or twin axle van. Lots of sites refuse them, even if you tow with a Chelsea Tractor.
My Toyota, is an unsignwritten company van, so I can't add windows.
So ****y, if you do have any joy / ideas, I for one will be happy to hear them.
Just found this http://www.vwt4forum.co.uk/showthread.php?t=285966
Searched for "Vinyl Wrapping Fake Windows" Search continues.