You may have a cause of action against the dealer, but it will depend upon what you signed, what they said to you, what type of extra items were added (the insurance coverages you mentioned do sound pretty unusual for a vehicle purchase), and most importantly what evidence you might have that misrepresentation was involved. Because if it is just your word against theirs and you signed all the documents, it could be difficult for you to prove your case, even if you have what sounds like a good case in theory. I would suggest to consult an attorney and explain all the details and go over all the documents that you signed with the attorney.
This answer should not be construed as creating an attorney-client relationship, and is for informational purposes only.
Consult with a consumer law attorney immediately.
DISCLAIMER: This reponse is for informational purposes only and cannot be treated as legal advice. Legal advice depends on the specific facts of the particular matter at issue. Accordingly, you should not rely on or act on any information provided herein without consulting with legal counsel that is licensed to practice law in your jurisdiction. This response does not create an attorney-client relationship between you and the Law Office of Arthur J. Obolsky.
This practice is sometimes called "loan packing" and has been found to be a violation of the consumer fraud act.
If this answer was helpful, please mark it as helpful or as a best answer. This answer is for general education purposes only. It neither creates an attorney-client relationship nor provides legal guidance or advice. The answer is based on the limited information provided and the answer might be different had additional information been provided. You should consult an attorney.