upgrading to 55w ballast

[umnitza]

Most oem ballasts for the X53 use the 9006 grey plug.
however, just buying a ballast won't do the trick.

The 55W ballasts we use make a marked improvement in our tests for light output on regular 35W bulbs.
Most OEM 35W bulbs are actually rated for a maximum of 60W of input without significant degradation in longevity.

However you will need an adapter to work with the AMP connector to D2S bulb.
D2S Adapters from AMP Connector [D2Sadpt01] - $29.99 : Umnitza|BMW Angel Eyes|LED Angel Eyes|Headlights|Lighting|Performance|Service|87748 66489

55W ballast link
Factory Canbus 35W and 50W Xenon Replacement Ballast [msbpb] - $34.99 : Umnitza|BMW Angel Eyes|LED Angel Eyes|Headlights|Lighting|Performance|Service|87748 66489