I haven't got any trouble with cops for tinting the front windows.
But when I parked my car at the police station parking lot, a cop gave me a little warning. He said no cops really care about the tinting unless I get pulled over for speeding or whatever. Then they will look over your car and pick faults like custom exhaust, header, licence plate, tinting, so on.
Tinting front windows doesn't stop the heat from inside because sunlight also comes in through windshield. My car alwasy gets hot during parked in the sun.