Does anyone know what % of light transmission there is on the factory windshield for an E60? My 2010 windshield has an AS-1 rating which means it must transmit at LEAST 70%of visibile light, but I'm not sure of the EXACT % of light transmission. I'm asking because I want to put a 70% tint on the entire windshield, but would only do so if currently there is 100% visible light transmission on the factory windshield to get to the 70% figure. Any facts or guidance would be appreciated. Thanks.