The term, "buyer beware," does not apply in modern American law. A misrepresentation or failure to disclose by a seller is grounds to cancel ("rescind") a contract, regardless of what the buyer knew or did not know about the transaction.
However, a good faith effort to disclose material facts by a seller will generally defeat the buyer's claims of misrepresentation or failure to disclose. From what you have described, you can prove that you disclosed, and that the vehicle was inspected by a third party. Therefore, there was no misrepresentation, and no power to rescind/cancel.
Based upon your statement of facts here, you do not have to take the vehicle back -- though, you may have to defend yourself in small claims court, if the buyer sues and tries to prove you misrepresented or failed to disclose.
There's no way to know what the buyer will do. But, I've explained your rights and the law, so you at least know where you stand.
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