If you have fun driving your car, you are probably a contributor to make the roads dangerous today. There is much more people dying on roads these days than in any war or wars combined. So, thinking a self-driving car would be more dangerous than the bunch of kids having fun driving too fast, not paying attention to the road, etc is pretty much an uninformed statement from your part. And on the other hand, there is a lot of people who haven't any fun driving, they even often are subject to road rage, in particular in heavy traffic with a lot of people trying to get the best and making it actually worse.
For the price tag, I would say once you scale something the price tag tends to drop pretty fast.
Lastly, an autonomous and self-driving car doesn't decide when and where you go, you still decide. Obviously you haven't yet assimilate the concept.
I'm sorry, but auto manufacturers have a point. Not anyone is competent to reprogram embedded car software. Unfortunately, bugs can be deadly. How would you feel about, say, 10% of the cars on the road running custom software by the next door kid?
Cars are killing much more people than guns. In fact, I would go further than the auto manufacturers. Nobody should be allowed to drive a car. How many people on the roads shouldn't have even a driver's license at all? A lot. And you are ready to see those people hacking their own car software? No way!
Scientists will study your brain to learn more about your distant cousin, Man.