As I was going to Warwick on Friday, I saw a newish looking Audi TT that appeared to have a U registration. The number was GMN544U. Now, as far as I know, U was never used as a suffix letter for registration years, but the Audi was RHD and the numberplates where of the new British type and did not appear to have been fiddled with. I also can't find any trace of the vehicle on the AA and DVLA registration search sites.
Any ideas what was going on? Is it foreign, or commonwealth? It was certainly strange.