I have had my 2013 Ford Focus w/ 73,000 miles for about a month and a half. I took it in a few weeks ago due to it shuddering and they did a software flash and reset. It drove good for about the first 3 days then started shuddering again and seemed to be a little worse. Fast forward to today I get the call from Ford after I dropped it off 2 days ago and they just told me the shuddering is within spec and there's nothing that they can do. What should I do now?