That is great! Seen a similar one with "no pasties" but that was only a sticker... these boys have taken the trouble to have it printed on!
My favourite sign on a van belonged to a firm of builders run by a family called Patel. "Fed up with cowboys? Try the Indians."
The best I saw was on holiday in the Caribbean.
A septic tank emptying vehicle had the slogan ...
"Number 1 in the number 2 business!"
Travelling down to Folkestone a few weeks ago , a builders van passed us ; someone had hastily written in the dirt on the van :- " I wish my wife was as dirty as this van" ;
Underneath someone else had scrawled "She is when you're at work mate" !
How about the inscription in the dirt on a white van: "Also available in white."
Nothing to do with vans, but on holiday in Canada we saw a sign for Beancounters Inc, a firm of accountants. Who says accountants have no sense of humour?