My apologies for the issue above - this information is in response to your question about your auto purchase from a dealership in Missouri.
Unfortunately, there is no "cooling off" period (or rescinding law) for automobile purchases in Missouri (this is a common misconception). You can find factual information in this publication by the Missouri Attorney General here: https://ago.mo.gov/docs/default-source/publications/knowyourrights.pdf?sfvrsn=4%20 (the information on auto purchases begins on page 18 of the publication).
It does appear that you were under "high pressure" sales tactics, and that they did get significant financial information from you (including information on your trust) in generating your loan application. You can of course try suing them for this, but my experience with these suits is that the majority of them are short lived - the dealership has retained well documented information for all of the loan application/agreement and purchase papers showing that the buyer has signed for these things (and the courts have a presumption that if the document is signed, the person signing the document has read it and understood it).
Obviously, an auto purchase is a significant investment, and it probably has a significant impact on your finances, you can ask a local attorney, or your local legal aid clinic, to review the documents that you have and see if there is anything improper on the face of the documents that may perhaps give you an opportunity to renegotiate the transaction.
You can also try filing a complaint with the BBB - the BBB acts as a mediator for consumers and can sometimes help you reach a more agreeable resolution.
If you believe that the dealership has acted fraudulently, you can report this misconduct to the State Attorney General - keep in mind, the AG's office is tasked with investigating and administratively enforcing business and profession codes, as well as criminal codes, they do not recover money for private parties (so they will not recover any money for you, or unwind your specific transaction, but they can investigate the dealership and potentially penalize them if they find wrongdoing).