a bunch of the guys on e92post have had it done to a 3 series - it is expensive and lasts maybe 5 years - longtran on e92post did his X5, flat black first, then took that off and did flat clear over his original shade of gray.

There is a pick of it in flat black here View topic - Thinking of wrapping my car in black vinyl...thoughts? | THE Mercedes-Benz & AMG Forum for and by the Enthusiasts | MyMBonline.com

Can't find a pick of the newer wrap he did, but done right it looks pretty killer, it is cheaper than paint and reversible and makes flat colors much easier to do - not to mention you can redo a section if something happens to it.