Now playing: Watch this: Top 5: Reasons automakers fear the autonomous future

For automakers, self-driving cars are at first a technical challenge, then an existential one.

Autonomy will change, and probably just plain shrink, the ways and the degree that we are attached to cars. Motorheads love to sneer at self-driving cars as "appliances" but that's exactly what they will be if they are going to deliver lower rates of fatalities, less traffic congestion, better fuel economy and lower emissions, not to mention a boatload of personal time returned to us to do something better than babysit a steering wheel.

But all that societal goodness comes at a cost to carmakers: an industry that may sell fewer cars and to a public that has a less personal relationship with them. Here are my top 5 ways carmakers are engineering their own brave new world, whether they like it or not. Watch the video for the full rationale.

No. 5 - Liability: It's very likely the auto industry will have to shoulder much or all of the liability for car accidents.

No. 4 - The first crashes: We cut machines no slack, so the headlines around the first autonomous accidents will be withering to whatever company made the car that's in the crash video.

No. 3 - Brand changes: We instinctively know what each brand of car stands for, but those brands will play a couple of decades of musical chairs when cars drive themselves.

No. 2 - Love of driving fades: Lots of cars are sold on pure, absurd emotional appeal. Autonomous vehicles seem less likely to inspire that.

No. 1 - Fewer cars sold: Autonomy promises fewer cars doing more work, instead of just parking all day. But yes: fewer cars.