My 04 cavalier passenger headlight is dimmer than the driver...the bulb is fine...seems like the reflection inside the (both new) unit is not reflecting or projecting light as it should...just started about 3-4 weeks ago

Its probably a bad connection. The high and low beam share a ground so if both high and low look dim then its the ground on that light. If its only one of the two settings then its the power coming into the bulb. Before you test anything, pull around the back of a nearby Superstore, like Walmart, at night and make sure both lights are facing where they are supposed to face. You say both units are new and I'm wondering if they are adjusted.

Thanks bro...Where's the adjustment...you try a get me cased up pulling behind a Walmart at night? Lol

There are vertical and horizontal adjusters both look like a torque bit. You will have to get an e-torq socket to turn them. You may be able to use other tools but they will also possibly strip the adjuster bolt heads. Torq bits also look like the star of david, or 6 sided star.

What John said and you mentioned that the reflectivity of the light seems less on one light. This could be due to the reflective coating inside the light degrading.

How can the reflectivity degrade so fast...they're only 5 months old...can it possibly be the angle maybe the lamp is sitting higher or lower than normal

If they are only 5 months old they just need to be aligned. The reflectivity should be fine. A good way to align them is to aim lights at a wall at night. Try to be about 25 feet back and adjust the aiming screws while watching the light beams. Or you can take it to a shop it's usually around $ 50.

I have a 94 cavalier and am wondering how to adjust the driver side headlight you can't seem to get to the adjuster on that side