There are at least two other people looking for it (of which I am one):
http://www.bbc.co.uk/...=110955990#p110953726
http://www.bbc.co.uk/...=110955990#p110954830
I only saw the trailer once, and can't find a recording of it on the BBC site or on Youtube. I know I've heard it somewhere before, but pretty sure it wasn't on an Eminem or P.Diddy (see 2nd link) track - that doesn't mean it's not either of them though, as the one I heard could have been the original hiphop/funk track they sampled. Aside from listening to every single Eminem & P.Diddy track, or somebody having recorded the trailer, the only other thing I can think of is to email the BBC, which I'll do. Though they don't seem to be too helpful with this sort of thing
http://www.bbc.co.uk/tv/faq/#detail
...
If I have any luck I'll post back here.