2011 Hyundai Sonata, 28k miles, car is 3 yrs. and 2 months young. Very well cared for. I drove car to local supermarket Friday night, very cold outside, car started fine. Car drove fine. Distance of approximately 3-4 miles to supermarket. Parked in ground level garage. Shopped for 20 minutes. Car would not start, engine would not turn over. When inserting key into ignition & attempting to start, engine only cranked about 1/4 and then silence. No clicking, none of the sounds you would expect to hear if alternator or starter were bad. All instrument lights on instrument panel came on, all lights and sounds were normal. Dome lights came on when entering car. Gas tank was almost full.I add a bottle of Chevron Pro-gard about every other tank @ fill-up time as per Hyundai mechanic's suggestion. Someone gave us a battery boost, car still didn't start. Headlights worked, radio worked, horn worked, 2nd and third jump start attempt also failed. Car is driven almost daily, almost exclusively highway driving, about 25 miles minimum highway driving. Tow truck brought us home after waiting 3 hours for Hyundai's Roadside Assistance. Anyone have any suggestions?

 

Under warranty. Let the dealer fix it for free.