I thought the phenomenon of the Bubba was a southern thing. I guess they've migrated northward though.

If someone who doesn't know you gets out of his vehicle already angry with you for an unknown reason, probably nothing you can say will defuse that situation. Think about it: even if you try something like "Sorry, buddy--just trying to get in a little exercise," he's going to think you're trying to make him feel bad about his eminently exercise-free self. No matter what you say, he's going to take it badly.

I know it's hard to clam up when someone verbally attacks you with no provocation, but when we're out on our bikes, we're pretty vulnerable, so best to avoid conflict as much as possible.