The elastic band fixings are at a bit of a stretch on the Mistral mirror but I recently bought a Raydot version which just stretches - try before you buy if possible. They should have an E11 stamp on them.
Caravan Club had a recent article about "the law" on mirrors a bit confusing - local dealer said it was wrong! , try their advise.
I think if you are going over the Channel you need to have them comply with EU standards