Contracts

Is a handwritten bill of sale acceptable in Arizona without notarization?
Is a hand written and signed bill of sale (by both parties) and not notarized acceptable in the court of law. Are there any states where a bill of sale is not acceptable in court unless it is notarized? In particular, will a non-notarized bill of sale be acceptable in Arizona's courts?
Can I get my niece to return the car after she failed the bar exam?
I promised to buy my niece a car if she passes the bar exam. She was exultant over how easy the exam was and assured me that she passed so I brought her the car. When the results were announce, she did not pass. Now that I asked her to return the car, she refuses stating there is no contract binding her to return the car. What can I do?
Can I cancel a car purchase contract due to repair disputes within a month?
If I have a dispute with a car dealer on the repair work of a used vehicle I have agreed to purchase, can I cancel the contract/sale all together if it has been within a month's time?
Should I consult an attorney before signing a release and trust agreement?
Do I need to contact an attorney before signing a release and trust agreement from an insurance company?
Can you break a lease within three days of signing?
If you sign a lease and change your mind within 3 days, can you get out of the agreement?