Could someone explain this to me? I'm hoping to get new headlights for my 93 325i.. The current ones don't shine very bright and I'm hoping to make the car look a little newer with the headlights..

How does this whole thing work? I'm reading things about not being able to install certain kinds with stock headlights or something??

I'm really confused, some suggestions would really be appreciated.

I suggest getting some euro ellipsoids if you on a budget get some depos, dj autos, or some apexcones. there very simple to install and take minutes and make your car lookin saucy

Assuming your lenses and reflectors are in okay condition, keep the lights and upgrade to 9012 HIR low beam bulbs in place of your current 9006 low beams. It will get you more light output than the Eurolamps would and only cost about $55. I posted a full explanation of this here, starting about the 5th post:

http://forums.bimmerforums.com/forum/showthread.php?t=843426&highlight=depo