I've got an 03 MCS with xenon. I've noticed the past couple nights that the drivers side headlight hesitates to come on or doesn't. When I turn the headlights off and on again it usually comes on without issue. Any ideas as to what is causing it?

 

the ballast may be going bad.

i wouldn't care until it actually went though, but that's just me.

 

There's been a few threads on this subject recently - have you tried swapping out the ballast with the passenger side?