Have you tried a deep polish?, get back to halliwell jones and have a chat with your salesman, he should be able to arrange their body man to give it a looking at with the polisher. Happened to us with a 3series a few years ago and nick (our sales chap) got it polished out for us at no charge.
If not and you want a recommendation I do know a first class body shop in saltney. He rarely does run of the mill stuff, usually e-type jags, ferraris, lambos and astons. Took my wife's 1 series to him after a slight bump and said he'd do it but couldn't get close to BMWs poor standards! He is good! (the etype job was £40000 just for the body and paint work)