Yesterday i test drove a Mustang GT as i get out of the car lot and down the road the car starts to not accelerate as good and getting kind of jerky and all of a sudden the engine stops, i pull over and try and crank it and it will not crank, it just turns over and over, also the battery light was on. This dealer has had the car for over 4 months could it be that the battery died while driving it? or is the car a no go?