CO law regarding auto repossessions when car is in litigation (filed complaint with Auto Industry Group)

If a car was purchased at an auction & then found the next day that the dealership failed to disclose major bodily damage (around $1500+) and potential structural damage (including all the fluids being filled improperly or not at all - that basically would have blown the head gasket, etc. and potentially the engine itself if any mileage put on), including failure to disclose all financing documents in a proper manner - does the purchaser (me) have any recourse in NOT paying the lender. (The first payment is due 12/9/08.) The car was shown and "sold" as a car with a warranty, then at time of signing when I was asked to sign a document stating that it was being sold "as is" and then questioned him, he said it had nothing to do with the warranty and that it was good; then the next day when the body damage was discovered & and one of the auction parties was tracked down & questioned about the body damage, he stated that all we had to do was call the warranty company and they would take care of it - which was a blatant lie we found out later. If I voluntarily surrendered this car (w/ no payments made), would I still be responsible for the difference owed on the vehicle if the lender resold it and applied that to the original loan - even though I have all these issues and have to wait over another month to get a response from the investigator with the CO Auto Industry Group due to his work load? Or what are my options? Thank you.