Yep, same here....we got an extra special offer from NWest (due to the type of account we have) and BMW, by some kind of miracle, matched that!
I've heard the same thing with most garages...they'll match any rate you get. Given the ease of getting quotes from the internet, thats what I'd do in future, just get the lowest and they'll match it!
As above, first quoted rate was around 13% (I tried not to laugh too much!!)