Offer tinted rear windows (rear and rear sides).
My Sienna minivan came with tinted rear windows, which I loved. As did my Volvo XC60. It’s too difficult to find a reputable tinter once we have the car (and I don’t want to have to leave my car for a day at the tinters).
Many luxury cars or even higher-end lines of non-luxury models come with standard tinted windows.
The Model X and Y both include tinted rear windows, standard as of 2020.