Thanks for the advise guys. We've done a lot of continental driving over the years, so have most of the kit (spare bulbs were also on the list to get).
However, she decided not to go in the end. There weren't enough other people wanting to go to the gig, so we were spared the hassle.
It does sound like getting the beam deflectors is going to be a pain though. I'll go up to the dealers next time