Sorry Ven - gave you a bum-steer. They were in fact 20 watt and purchased off eBay about 4 months ago. Listing is no longer live, but I'm sure you'll be able to find other sellers offering something similar. Mine came with aluminum ballast resistors, with a nice heat-sink on the outside. I simply cable tied these to the excess wiring and slipped the whole mess inside the aperture where the OEM lights were. Here's the original listing info. Suggest you copy, paste and search on eBay.
20W Cree LED Angel Eye Halo Ring Marker Light For Bmw E39 E53 X5 E60 E61 E63 E87

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08/06 build 4.4i Stirling Grey over black