70° is what these paints are designed to be painted at. If you are painting at 60° you need a really fast evaporating reducer for the basecoat so that it gets off the surface fast instead of running down the inside of the engine sidepans and core support as each coat is setting up.
Either wait till it warms up to 70° to paint, find a garage to roll the car into and heat the garage to 70°, or string up a temporary structure with plastic over the top and box the sides in with plywood and blow some heat in there with an electric heater or whatever.
Can't paint with too low of air temp, just like you can't paint with too small of an air compressor. It is trouble all the way around.
