> Economies of scale. Autonomous cars will likely be of a different design than manual ones so the price of a manual-drive will likely increase- where will the increased money to buy them come from?

The people who continue to buy manually driven cars, I presume.

> Insurance costs. Drivers in less-dense cities are currently safer than the national average: what does the risk and cost for a safer driver become now that the bad urban driver benchmark disappears?

They will be benchmarked against more dangerous suburban drivers (e.g. Marylanders) instead.