PLEASE HELP CAR AUTO LOAN.?

i bought a 2008 scion tc back in april of 2008 from a used car dealer. The car had 554 miles on it making it a used vehicle. I go to trade the car in 2 weeks ago to toyota to upgrade to a rav4 and the gentelman who inspects the vehicles before trading it in states the car was in a COLLISION back in Nov 2007 and therefore they cant take the car back. The whole back of the car has been replaced with after market parts the trunk the rear windows and the rear axel. To my shock i have never been in an accident im driving 13 years thank god. Went back to the dealer i purchased the car from and he said theres nothing he can do it was sold as used. No carfax was provided back then and now that im looking to upgrade no dealers want the car in trade. I have been told by a autobody shop owner that on the sticker its supposed to state collision repaired not sure if thats true or not but on the sticker it doesnt state that. What can i do as far as either getting out of the loan or getting rid of the car. Please advise.