I've done the Chunnel in my old D2 several times and the D3 twice now. I just fold the mirrors in and its no problem, the only dodgy bits are as you drive past the toilets every other carriage. This year I am taking the Volvo S60, but not travelling to Le Mans.

Much rather be with the cars than the coaches, with the coaches it can be a long walk to the loo and as there are so many people with hardly any loos there is usually a queue.

Just went through the Chunnel on the way back home. Was fine again, but just with the extra threat of kerbage. Didn't think about putting the mirrors in.

Probably wheel spec dependant. Both the s5 and S8 are on 20s and the risk of kerbage is quite high! Managed the S5 down there ok but there's only a few inches either side. S8 with spacers I doubt would've fitted without damage