These guys are probably the ones likely to be hurt the most. A handful will survive, since tires, brakes, and oil still need fixing; general wear will always be a thing. However, the numbers will certainly diminish, as accident-based work becomes less common.
Less common? No, someone will have to repair all the autonomous vehicles that get rear-ended after they have a sensor failure and they stop unexpectedly as a precautionary measure.
...these cars run on wishing dust now? Unless you've got a self-driving Tesla, you'll still need gas.
More people going more places because it is no longer a tedious thing to drive to Gramma's house or the country or beach. And more autonomous cars put into "drive around until I call you back" mode because it costs too much to find parking, if you can find it at all. More gas will be needed.
Dear Lord. it's entirely possible to load precise cannons with basketballs that will land perfectly from half court, every time...but that's not why people watch basketball.
The only "motor sport" I can think of that will be affected by autonomous vehicles is the sport of standing by the side of the road trying to fool the car's sensors into thinking there's a baby in the middle of the road so you can watch the chain reaction/collisions. (And this is truly one of the times where "affected" and "effected" are both correct!)
No other motor sport would include autonomous vehicles. That's why it is a "sport".
Motor vehicle related advertising
You're right - that will become "in-car advertising", but now we're just changing location.
No, advertising about cars will not stop or become less common. In fact, more advertising will be used to hype the miraculous safety record of these new-fangled autonomous vehicules and to try to convince people to abandon a perfectly functional manual car in favor of them.
Here's another: highway maintenance crews - the ones who pick the trash up off the highway. I anticipate less litter if "immediately ridding your hand of a wrapper without also needing to look for a place to put it" becomes commonplace.
That's not why people throw trash out the window. It's more a case of "if I don't throw it out the window, I'll have to clean out the car later...", and that won't change.
I wonder about sign manufacturers - who's going to pay for a whizbang storefront sign instead of just paying Aunt Google more to come up in search results,
Whizbang storefront signs aren't there to tell you where the store is, it's there to attract casual passersby. Either to get them to say "hey, that store looks interesting", or "hey, I need to stop there". Otherwise all they'd need is a simple sign saying "Joe's Eats" so you know which door to walk in after your car dumps you on the sidewalk.