Tried search but didn't come up with anything...and I want to make sure I know what's up before buying (or helping others) buy Xenon kits for cars that run 9003 bulbs.

Just to see if I understand correctly, bi-xenons run two ballasts, and they move in/out to either have low beam (in HID) and high beam (also in HID).....

And Hi-Lo is when the low beam is a HID bulb and the high beam is a standard halogen bulb mounted directly ON TOP of the HID low bulb...

Is this correct?

 

From what I've seen there are three versions of "bi-xenon" pnp bulbs. One unit uses two hid capsules in each bulb and requires two ballasts per bulb. Another uses a moving shield with a solenoid that moved the lower shield out of the way to allow light down into the high beam reflector (one bulb, one ballast). And the last is a fully shielded bulb accept a small port on the bottom side where a solenoid again moved but just the glass capsule this time to move the bulb into "correct" high beam location just above the opening in the shield.

Halogen high hid low is commonly used (some people just say high-lo kits, some don't specify but sell it this way and some say halogen high, hid low) the bulb uses the lil halogen bulb on either side of the bulb to act as a high beam bulb. I got a set of 9004 (I think) for my buddies focus and even tho the halogen bulb was no where near where the original high beam filament was it did a damned good job a high beam output..

For the most part you are correct, you need to verify with the seller that you use...