I asked about one in the states, I was told Club Car had a solar top......something like $2500 USD.I'm not sure if it is actually Club Car brand or the dealers are just selling them.

I had actually thought about building something like that
-then I did the math and decided it wasn't worth the money or effort for the little bit of extra power one cou;d provide.

Here is a link: http://golf-aid.com/product_info.php?products_id=820