i'm not sure if rental cars are a good example of the cars though... rental cars get abused and are usually worn out--- and i've never seen a new car at a rental place.
However if you can find the exact same model at a rental place, It would probably be a good idea. After driving around for a day or two you may find something out about the car that you dont like or something you do like that will really make you want it even more.
I'm currently looking into getting a nissan sentra specV, i've only actually driven the car for a total of maybe 30-40 minutes, but i love and nothing will stop me from getting it. 🙂