Difference: 2003 to 2005 models had EITHER Halogen lights OR Xenon HID. 2006-2009 models all had a Bi-Xenon HID setup. The lights you just got are probably 6-pin Halogen for use in the earlier model.

FYI, the more desired lights ARE the 2006+ lights which your car already has. Why are you replacing the headlights? If from damage, they'll need replacing. But if it just that the lenses are crazed (also foggy, scratched, basically wonked), they can be polished and rebuilt OR if replacement is necessary, your two choices are OEM or DEPO brand. The rest are essentially garbage.

 

Replacing for swag points from buddies

 

 

Wet sand with 600, 1000, 2000, ++ then polish it and it will be better than new. Hit it with some good UV protection monthly especially if it isn't garaged

 

If you can't return the headlights you just bought and don't feel like wet sanding, you can always swap the lenses. A little more work than polishing them, but another option.