Here are the laws in TX for front side windows.
Side Windows to The Right and Left of The Driver
Sunscreening devices can be applied to the side windows to the right and left of the driver if the following conditions are met.
Sunscreening devices, when measured in combination with the original glass, have a light transmittance value of 25% or more.
Sunscreening devices, when measured in combination with the original glass, have a luminous reflectance value of 25% or less.