Are there any differences in the headlights between the 04/05 and 06+? I know the bumpers are different but are the headlights too?

Yes. One noticeable difference is the amber markers. The 06+ are narrower compared to 04-05.

Anything other than that?

The plastic that projects from the medial side of the housing is different; I suspects it's due to the grille difference between the years. I also read the HID hardware in the rear is a bit different. IIRC, by a screw.

You're specifically asking about the headlights? The surfaces of the low beam projector lenses were polished smooth in 04-05, for 06 they became cut with a fresnel surface instead.

We'll I'm asking about the physical differences that are noticeable. I'm looking at an 06 TSX but it has an 05 bumper instead...it must have suffered a minor front end accident (though carfax/autocheck comes clean). The car is 06 everything including the hood...headlights from what I can tell do also look like its 06...but I just want to make sure.

Does the grille in the old bumper look odd then? It won't have a chrome "top", right? I'd love to see a photo if you can get one...

Yup, it sure looks like an 04/05 bumper on an 06+. I gotta say, that looks really good!!! Are there any odd gaps where the front of the hood meets the grille, especially the two sides of the grille?

No idea. The seller insisted he purchased the car CPO'ed like that and that there's no difference. The car was a good hour trip away from me and the fishy story strayed me away. So I didn't get to check in person up close of the fitment.