Its Peake, and they work well. What you need depends on whether the OBDII port is under the dash [as in my 2006] or in the engine compartment [as in my 1997 E36]. I bought an adapter for the Peake I bought in 2001 or so for my E36. You might check ebay but to my mind its worth the $100+ investment through Pelican, Turner Motorsport or similar on-line vendors.

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2006 X5 3.0 6-spd w/Evo UUC ssk
sport/premium pkgs
born Valentine's Day, 2006.