You can get appliance epoxy in rattle cans at Ace in various colors. I tried some on a headlight knob, it seems to be hard as a rock.
Yes, paint will wear through again - probably in about 20 years, just like the original.
BTW, those steering wheels aren't plastic. They're a very hard rubber material. Trust me, you can tell a plastic steering wheel - they crack into a zillion pieces.
