Rob I do agree with you and John about having a sweeper car, in theory But in practice it would not work 100%, what if you have a team that have strayed off track and are making their way back via different roads than the recognised route, (or worse case broken down on some out of the way road) the sweepers can't cover all the roads. But like you say there are contact numbers (if you have signal of course) We had it a few times in 2014 where we was late for a control, most were still there waiting for a while, one had shut up shop and gone, (no fault of theirs) so we continued anyway, then we heard rumour via another team who called me, that 'the renown is out of the run' (not so of course) So if the marshal for that point or any heard that rumour, then they would not bother waiting any longer than needed if we was the last car or not. Like John said, with modern technology now, we can just take a picture of that check point to prove you was there.