MBUSA is for, well, the USA. Might try Mercedes.Me
for the UK or maybe this outside site
(have no idea if the second site is any good).
I just let Bing do the search for "Mercedes Recall UK", most of my time was cutting the MB URL down to something manageable.
ps remember being at a security conference in Vegas (with my "I am not a fed" card) when some kids came in pitching something called "google" as a replacement for archie.