Van derived minibuses are common and they don't warrant an explanation of surprise normally!
However I've found a lorry derived coach, not even a coach on a lorry chassis, I guess this is basically a big welfare bus? Makes you wonder what advantages this has compared to either a coach with wheelchair lift or longer bus with extra wheelchair spaces!
Take a look...
http://www.ebay.co.uk/itm/DAF-LF45-...K_Minibuses_Buses_Coaches&hash=item27de167daf

Take a look...
http://www.ebay.co.uk/itm/DAF-LF45-...K_Minibuses_Buses_Coaches&hash=item27de167daf