I have the same car as Brandon002, and unfortunately my mechanic informs me it needs a new AC compressor. He also said there doesn't appear to be an alternative to the dealer version (for $1350) - there isn't an aftermarket one, but he's continuing to look in case one becomes available.

I don't doubt anything he says - he's very good and knows these cars inside out - but I'm still trying to search on my own. It looks like this is the right part, and it would explain why he can't find a Denso replacement. Can anyone confirm this, please?

2004*BMW*X5*A/C Compressor from DiscountAcParts

64526917864 is the BMW number.

TIA