Not a chance. The surveillance cameras on wheels are so cheap to query that you might as well be analyzing the streams constantly, and have them tell you when something interesting is happening.

No way. You have to convince each human to give you the information that you want on a case by case bases every time you want it. We suck at that even when we're being cooperative--which in many cases we aren't. With cars you can just collect it all by default and search for what you need after the fact.

A network of spies is far more expensive to maintain than a network of cameras, wheeled or otherwise.