You are right to be looking for lawyer in the state where you bought the car, and if your initial inquiries are unproductive, consult the National Assn of Consumer Advocates (www.naca.net) for a lawyer experienced in vehicle purchase cases.
You are in a difficult situation because by at the time you signed the contract, it did disclose the price, even though that was different from the advertised price. You cannot cancel a contract just because on further reflection it was a bad deal. But considering the entire transaction, a lawyer may be able to find examples of misrepresentation about the car or defects in the paperwork that would give you some leverage in trying to unwind the deal.
Disclaimer: This site exists to provide information only. It is not legal advice. Answering your question does not create an attorney-client relationship. I am a Massachusetts lawyer. Any information provided on this site does not, except as explicitly stated, imply familiarity with laws or procedures peculiar to your state which may differ from those where I practice.
Its possible that you may have some claims under the Truth in Lending Act, Massachusetts Retail Installment Sales law, or the Massachusetts Consumer Protection Act. Dealer's must disclose everything involved with the purchase to you before you sign. It sounds like that might not have happened here.
You should consult a consumer attorney who practices in your area. Many will give you a free consultation. You can find a directory at www.naca.net.
You should definitely consult a lawyer with experience in consumer protection issues. There are several pages in Code of Mass Regulations (CMR) which prohibit the conduct you have described including banking, truth in lending, automobile sales and advertising.
Get the car inspected properly. Also, it may just be possible to void the sale.
The foregoing answer does not establish an attorney client relationship, is not confidential, and should not be relied upon in place of an actual consultation with an attorney. Mr. Boone is licensed to practice in Massachusetts, before the U.S. Tax Court, and the Federal District Court of Massachusetts. Most initial consultations are free. Further information is available on my profile and at www.boonehenkofflaw.com.
Make sure that the attorneys that you are contacting are experienced in consumer law. You can find a consumer law attorney here: www.USLemonLawyers.com. Just scroll down to the attorneys listed for NY and NJ. Hopefully your search is successful and you can find someone to help you get out of this vehicle.
Did a business treat you unfairly? See what your Consumer Law rights are to protect yourself: http://tinyurl.com/9aqykfo
Click here to see what your state law says is unfair and deceptive and what your legal rights are: http://tinyurl.com/8pnvdot
What is fraud? Click here for a “plain english” explanation: www.carsalesfraud.com
This answer is for general purposes only and does not establish an attorney-client relationship. The law in your state may differ and your best answer will always come from a local attorney that you meet with privately. If you need a Consumer Law attorney, click the link above to find a Consumer Law attorney near you.