as long as you're happy to make burnout comps 'motorsport' too

even show'n'shines have cars with motors competing against each other. doesn't make it motorsport.

some of those night runs/ touring assemblies/ nav runs or whatever else you want to call them have a skill test to decide a winner in event of a tie. They set up a pole standing up in a parking lot, and the competitors drive up to it and stop as close as possible without hitting it. It's a test of skill, a driving competition between motor vehicles, but it sure as hell ain't motorsport.

As for freestyle motorcross, that's just gymnastics too; the motorbike is merely the apparatus and is purely incidental to what they're actually doing. Guys do exactly the same things on pushbikes. Maybe that's motorsport as well?