Now it's starting to get stripped. I"m not an auto mechanic, what would you do in this instance, use a torch to free the bolt out of there?
Earlier this year a repair shop declared I needed new calipers and I obtained some, but I salvaged bolts from the front calipers, hopefully I can use one of those to replace the rusted one.
Is rust the enemy of auto mechanics?

Ironically there is almost no rust underneath my van, only on the wheels near where the brakes are.