I think they would have great potential as information portals on hybrid vehicles, all you would need is some nice clear pictures of vehicles, specs etc and run down to your local dealership to make a deal. You bring in the buyer you make a good portion of the commission.
If you get good results in search engines and your website is properly managed with contact / forms everywhere then you could make a few dollars per lead or a few thousand per sale depending on your deal with your hybrid dealer of choice.
Wouldn't take much to make a few grand per year with such a website. Dealers would be more then happy to come on board as another sale threw their business is good business even though you are getting a good percent of the commission.
There is also car finance available specifically for hybrid vehicles, so there maybe an opportunity to generate leads there also for the brokers ($50 + per good lead).
Good luck!!!