When I was a coach driver, we had to check the vehicle before leaving our last stop and quite often we had to 'remove' people from under, in lockers and even inside the coach! We had a check list form that required a counter signature - ie a passenger - which would rove that we had checked the vehicle. All very well, but if someone was to get onto the vehicle after the check had been carried out, this would have implicated the passenger as well in the event of being found by Border Control! We often had to wait whilst the passengers disembarked the coach and go through passport and custom controls while Border Control checked the coach. I used to point out the favourite places where these people could hide, as they didn't seem to know where hide-away places were, especially in the spare wheel compartment! Carrefour at Calais was a favourite place for these migrants to get on vehicles and hence we were always aware of the problem.