UCAN

My husband and I purchased a vehicle from a private party in Minnesota. It was a 4WD truck. We took it for a test drive, and I was concerned that the 4WD might not be working. The seller indicated that it was working. We purchased the vehicle for $1200 with a check, but the seller did not have title to the vehicle and said he would turn the title over when he got it. We drove the vehicle home and started having problems with it. It overheated and we were having problems with what seemed to be related to the 4WD. We took it to a shop and they said the 4WD was not working on the vehicle. So, I stopped payment on the check and the next day, we proceeded to drive the vehicle back to the seller. The vehicle broke down on our way, and we had to have it towed. While it was being towed, I followed in another vehicle behind it and noticed that the vehicle seem to have a rather wobbly wheel. We stopped and looked at it. All but one lug nut had broken off and the tire was about to fall off completely! The seller had tried to cash the check and it was returned because of the stop payment. However, it appears that he then scratched off the check number in the upper-right and in the micr encoding, and cashed the check again, and this time, it cleared my account. The bank is currently investigating the stop payment issue. My questions are:

1) I realize that a sale like this is "as-is". However, since the title has not actually been signed over to me, what recourse would I have, and am I likely to be able to return the vehicle and get my money back (give court battles of course)?
2) If the check numbers were scratched off, is that illegal? How likely is it that the bank will honor my stop payment request (Wells Fargo account)?