4 Wheel Drive/SUVs: Rav 4 piston rattle, toyota rav 4, service appointments

Question
I have a 2008 4wd 4 cylinder Toyota Rav 4 that I bought new.  I had this rattle from just a few months in owning it.
After numerous service appointments the engine rattle got finally diagnosed as a piston rattle in the engine.  I was told there was nothing that can be done that some of their 4 cylinders have this "characteristic and has no effect on the engine performance".
So basically I am stuck with a car that rattles under a full warranty.

Help what are the ramifications of a piston rattle and what should I do. Shouldn't the warranty cover this. I do not want to drive a car that has an engine that rattles that cost over $22,000.
Thanks for your help

Answer
Cheryl, there is no reason that you should have to drive this vehicle how many miles are on it? If it has a full warranty I would tell them to shove it where the sun dont shine, lol The lemon law only works if the vehicle has 24,000 miles or less, but either way just go in and mention the word lawsuit, and they will more than likely be willing to do something . ADAM