If you are still looking then you occasionally see the Mu SL on Ebay UK.

If you want something a bit more special then I was in touch with someone about 3 months ago who had a Mu EX for sale. It was 2[SUP]nd[/SUP] hand of course but it was owned by someone who is a relatively well-known cyclist who won the Smithfield Nocturne in 2010 on this bike. I believe it is mostly standard except for the seat post and saddle from a Tern I think. The seller is a share holder in Dahon or Tern, I cant remember and I think now sells Tern bikes In the UK.

If you want to know more about the bike let me know and I can find out for you.