[samolang]

How big of a solar panel would you have to stick on top of an electric car to keep it going forever (ignoring the extra weight/wind resistance)?

[QuercusMax]

I suppose it depends on your definition of "car", but they've been doing this for many years in the World Solar Challenge. GM's Sunraycer drove across Australia in 1987 on solar power alone: http://en.wikipedia.org/wiki/Sunraycer.

[samolang]

Yeah, I meant more like a Tesla or Chevy Volt.

[Meredith023]

I think 2*4 will do the job just fine but you may want to check with the folks at http://www.onlysolars.com/ for this.

[maxerickson]

It becomes important to decide how much it weighs and how fast you want to go (and if it has to work at night in Alaska...).