Regarding the service history I wouldn't be surprised if they took you at your word for the purposes of a quick valuation but would check its authenticity come deal time. Also, when I went to VW when I was hunting around for my next car they had a print off of my last cars VW history to hand off their own system.
Would have thought BMW were the same?
Independent or reputable chain to OE requirements, maybe
DIY to save a few quid on a two year old car, I wouldn't
