Just notuced that the two question marks for caravan are from our friends over the pond and maybe don't get the wordplay, so I will explain
Over here guys, we call a caravan that is parked on a site 'a static caravan' which is different from the ones used by people who tow them each time they go on holiday, which is called 'a tourer'.
Over your way, I think you refer to them as a trailor, as in trailor parks.
The 'perhaps with a question mark' was placed at the end of the clue because it negated it's true meaning from the clue word 'travelling'. A sort of way to say it was not as it seemed.
Hope that was ok for you, I think the Brits would have picked that up much easier.
The UK/US anomaly is a teething problem and may have to be considered in future efforts.