Actually, you must be 18 to enter into any kind of contract, even if the deal was never made in writing. So him selling the car to a 17-year-old was illegal to begin with. Find an attorney who's willing to put this in writing– shouldn't be hard to find one who will do it cheap or even free. Let him read the attorney's statement that the contract itself is null and void because one of the parties is a minor; that should get his attention and if he still doesn't refund the money, take him to court. But be careful— you want to take him to court on the fact that he entered into a contract with a minor, which is indesputable. You'll win. Don't bring up anything about the condition of the car; you'll still win because the contract is still void, but you'll have more arguing and fighting.

Absolutely. check for a lemon law. unless of course she bought it as is with a written contract, or even a verbal contract in some areas.

If the odometer was turned back she potentially has a case in small claims court. If it was from a dealer, and depending on your state, you may be able to get your money back. Otherwise, used cars are sold as is and she should learn to really research the car she buys before she puts money down, and if she's really into one that's in the lower price range (under $3000) she should have a mechanic look at it before the sale is final.

Really kind depends on when she bought it. You can always use the lemon law, I'd check with the Sheriff's department about it.

Probably not much of a chance unless she can prove there was fraud, can afford to hire a lawyer, and if the guy has enough money to make it worthwhile.

If the odometer was wrong, he committed fraud. Check with the DMV in your state.