The temp gauge suddenly jumped up and alert said coolant was low. Driving on freeway, car shut down before I could get into a shoulder. Big rigs swerving around me, could have been killed. No leaks under car. Cap off the coolant reservoir and the coolant level bubbles up back to normal. After that, even driving one mile makes the temp gauge jump up and drop down erratically. Quoted more thank $8,000 to repair because it requires a new engine? Ford dealership said this is very common issue for Ford Fusions, that it is a design flaw and many of their clients have had similar safety scares.