Hector, I have noticed this on several cars that like the one in your photo are fairly new and have the lettering faded , it does not take a rocket scientist to understand why. too many speeding fines from cameras. I know for a while in Canada one could buy a plastic "Protective" cover for your plates that made the plate only readable from a low angle. I think it was a $200 fine for having one on.
On a side note last Thursday I was pulling out of HGV on to 205 and noticed this unusual sporty looking car behind, one does not see much of these in Korat, so as I moved over to the U turn lane he passed me on the left, it was a black car with big letters Highway Patrol on the side and Police on the back, with the candy bar on the top (RED flashers), not sure if it was real or not,being that it was a Ford Mustang! first one I have seen in LOS.
KC