So what is the outcome of your situation?

Most people can understand your issue however you signed a contract which you should have taken the time to understand before signing. To then decide the purchase was a big risk based on internet postings and cancel the contract you didn't read!! Chances are you had a perfectly good car that was well maintained and which would have had a warranty for probably 1 year.

Your chances are extremely low.

Rushing in to a purchase and doing impulse buying should be limited to low value transactions.

In our first year here we went through the process of buying a car but waited till about a full year and then yes did miss out on getting one of my preferred purchases. The reason i missed out is that i didnt have an interpreted version so I manually typed and intpreted the contract and took it to someone who was native german. Yes I missed the purchase but when I signed the next one I knew what I was signing.

This may be a bit slower but its worth the effort so I suspect you have limited possibility unless the dealer feels nice. They are well justified in saying that you should have checked everything first rather then making a rash decision to cancel on the strength of internet postings that you are yet to know if your purchase was even susceptible to.