The car is on the sun side of space as seen by the lens flare. This means that the car will absorb high amounts of radiation, heating the car up to well over 250 degrees Celsius . A car windscreen will start to crack at around 120 degrees Celsius , most certainly not surviving at 250 degrees Celsius . Satellites need special radiators and a special covering because of these high temperatures, but this car has nothing to help with the dispersal of heat.The car is also traveling through space at over 12 miles per second. But the car's windscreen does not have a crack even after four hours. Also if the car is spinning as mentioned (shadow cools in space / sun heats up) wouldn't this create another problem, the windscreen would be in thermal expansion on one side, and contraction on the other, so why doesn't it crack and break?
The Tesla Roadster is not experiencing 250°C temperatures.
This answer to another question shows that in Earth orbit it will be just over 0°C, similar to you and me:
The key plot from that answer shows that out near Mars it will be around -80°C
It doesn't crack or break, because it's made of inorganic material. Chemist Richard Sachleben states in this article from Life Science Will SpaceX roadster survive Space that it will take a long time for the windshield to discolor and come apart relative to any organic material in the car (leather seats, rubber tires) and will only start to do so as the plastic in the windshield starts to decay. He believes the organics will last around a year, but gives no specific guess on the glass.