This has been discussed many times...

But, on the pre-LCI trucks they used a light tube setup similar to the e39 5 series and e53 x5. It does not transfer light equally between the rings due to the shape and distance from the bulb each ring is.

There is NO way to get equally bright angel eye rings by just swapping a bulb. You will have to open up the headlights and do a retrofit of some sort. This is what I ended up doing on my E53. It looks amazing but is one of the hardest mods you will do.

__________________
2005 X5 4.4i Build 04/05 Maintenance/Build Log
Nav, Pano, Sport (Purchased 06/14 w/ 109,000 miles) (Sold 8/15 w/121,000 miles)

2006 X5 4.8is Build 11/05 Maintenance/Build Log
Nav, DSP, Pano, Running Boards, OEM Tow Hitch, Cold Weather Pckg (Purchased 08/15 w/ 90,500 miles)

2010 X5 35d Build 02/10
Nav, HiFi, 6 DVD, Sports Pckg, Cold Weather Pckg, HUD, CAS, Running Boards, Leather Dash, PDC, Pano (Purchased 03/17 w/ 136,120 miles)