Ohh I remember the initial AirBag Recall thread, one of the main complaints when people got their cars back were these exact scratches.
Yeah, its because the airbag is awkward as hell. When you are putting it back in, the wiring doesn't want to fit right into the holes through the steering wheel, so you end up dropping the airbag forward and out of the wheel while trying to pull the wiring harness through and scratch your plastic. I just did it to mine this past weekend. Sucks!
If they had just put some simple tips in the instructions, all this could have been avoided. I suggest the following:
1. Tie some rope onto the airbag wiring harness. This will allow you to put it through the steering wheel and easily pull through.
2. Put painters tape over the plastic piece on the wheel.
Seriously.. had they put this, I bet they would have saved thousands in repairs. When they did the airbag on my original car.. they replaced the plastic too because they messed it up.
I may try and experiment with spray paint / 3m putty and see if I can fix one of my messed up ones. Just because, you think you could easily enough.