Final answer:
The required percentage of light transmission through front seat driver/passenger windows varies by location; local laws must be consulted to get the exact requirement. Market share information for windshield replacement is not relevant to this question.
Step-by-step explanation:
The tinting on front seat driver/passenger windows must allow a certain percentage of light transmission which varies by state and country regulations.
The regulations ensure that visibility is maintained for safety reasons while driving. There isn't a universal percentage; it can range from as high as 70% to as low as 25% light transmission. Therefore, to get the correct percentage, it would be necessary to check local regulations. The market shares for replacing automobile windshields information provided does not directly relate to the question about light transmission percentages for window tinting.