Owner of a VW Up, 18 months old have done 4500 since new. Took it on it'/s first long journey on Saturday (about 130 miles one way). On the way home half an hour into journey the coolant light pinged on and was flashing. Pulled over four miles on at services. Manual said do not drive. Checked coolant level looked normal. Waited 2 hours for AA to come out. AA chap couldn't find anything wrong with system etc. Decided to risk it as a further two hours wait to be towed home. Got home without this happening again. Drove at a steady 50 mph. Car has been at VW since Tues. They claim that after extensive testing no fault found. Anyone else experienced this as will be making this journey on a regular basis from now on and need a reliable car?