Hi Steve, from memory they have different evrsions of BF, definitely turbo and non turbo, maybe even different cars e.g. would ford turbo BF work on VAG car? So if you second hand make sure 1) Its been reset, 2) its been used on aturbo car and 3) its been used on a VAG turbo car.
Finally if you are a member of the UKMkIV forum you get a 10% discount, got my BF for £400 about three months ago and its brand new and total piece of mind - just a top tip!