I have a 2007 E61 LCI 523i.
VIN decoder tells me that I have option S694A on my car [Provisions for BMW 6 CD changer].
realOEM.com tells me that the CD changer unit I need is 65129131850 (plus the cartridge)
http://www.realoem.com/bmw/enUS/show...diagId=65_1312

Question: If I buy one of these used, do I need to code it to my car, or is it plug and play?
Also - I see some of the units on ebay include a clamp. Do I need this?

Thanks.
MtM