PS. On a not unrelated subject, we got home yesterday afternoon after a long weekend in Yorkshire (Huddersfield area and Leeds) for a family wedding. We came home via Manchester and somewhere on the M6 overtook a Transit based camper whose pop top had lifted open a good 4" at the front. Unless both the driver and passenger were as deaf as me, they must have been able to hear the wind noise but I did open my window and point it out to them. That said, we kept going and I've no idea if he pulled over or that was the usual state of their roof. I kind of wish that I'd made a mental note of the time we saw it but I didn't - my rear camera records in 3 minute segments and to find the relevant footage from when we went past them in amongst all the other files just fell into the too difficult category or I would have posted a still photo.