Plastic-dip it!
Out in Colorado we get a lot of rock chips and the panel below the headlight seems to get hit hard. My 99 T4R is littered with chips. To prevent the same on my black 06 I decided to Plasti-dip the panel black and add the glossifier. The finish is a slightly off from the body paint but it's close enough.
Removal of these panels on a 4th gen is simple but be careful not to break the clips located on the outer edge of the panel.
Removal steps
1. Open the hood.
2. Remove the plastic clip located at the inside (grill side) lower corner of the headlight, which is behind the grill when it's closed. Use a flathead screw driver to carefully pull out the center portion of clip. Once the center piece is out a bit the rest should wiggle out by hand.
3. Pull the panel towards you and away from the mount point about an inch or two, but no more.
4. Once at the position shown in the photo gently pull the panel towards the gill location (e.g. the inside of the vehicle and parallel to the bumper) while wiggling it up and down just a little.