I was lucky enough to find some at a local yard a while back. Unfortunately, they broke into a million pieces when I tried to remove them, because of how brittle they were from sitting in the sun. I ended up epoxying all of the little broken shards back together and they are on my car now (though I dare not try to remove them). Would recommend only if you are a masochist. Otherwise, be very careful if you find some and want to remove them - I'm sure they're all brittle.
I was going to model them in CAD and try to 3D print my own, but gave up on modeling due to the complex curves and the problem of 3D printed parts softening or melting in the sun. Might pick it back up again though.