2018 Acura MDX Advance SH AWD
I'm not sure. Just looks like buildup/gunk to me. You could always use Vaseline. Or motor oil (synthetic). I wonder if Johnsons paste wax would protect. I've seen Jeep guys who cover their ball joints, rod ends, bushings in thick jelly like oil. Looks like absolute garbage but highly effective. I'm glad you brought that up. That reminds me to take my chrome crossbars off for the winter this weekend so they don't rust. (Cheap foreign steel that rusts).