I liked the idea of a more 'environmentally friendly' car, so we bought a new Prius in 2008. Turned out to be a very expensive mistake. Just a few days after I bought the car, the "multi-function" screen failed and was replaced under a warranty. Then it failed again, this time just after the warranty expired. Repair cost? $7,000 - yes seven thousand dollars! The Blue Book value of the car is about $15k. So a relatively new car (37k miles) cannot be repaired for economic reasons, as the cost of a relatively minor repair is about half of the car's value. If this is not a classic example of a lemon, I do not know what is. The "multi-function" screen itself is of little functional value, but its failure makes the heat & AC control rather difficult, which poses an obvious safety hazard while driving.
But this is not the end of the story. After doing a bit of Googling I found that the problem lies in the faulty design of an electronic board, and that Toyota knew about the problem and quietly fixed it (or so it claims), but it continued to rip off their customers by charging them $7k for a replacement of what is an equivalent of a $200 computer mother board. Details are here http://www.techno-fandom.org/~hobbit/cars/mfd/ . Some disgruntled Prius owners suggested a class action suit, but but I do not think this went beyond kvetching on chat lists.
Two things struck me while researching this problem. First - the design fault in Prius electronics was discovered by some amateur rather than the NTHSA or even Consumer Reports which are supposed to look for these things to protect consumers. It looks like the consumer protection "watchdogs" fell asleep behind the wheel, again. OTOH, the last issue of Consumer Reports does rise safety concerns about electronic gadgetry in new cars, the unfortunate trend that Toyota started. Second, it seems that "environmental friendliness" of the Prius is overrated if not illusory. The pollution from faulty electronic gadgetry that ends up in a landfill probably offsets savings by slightly better fuel efficiency. Taking the transit is much better for the environment than buying even the most "environmentally friendly" cars.
Wojtek