there are things that can be done, but most include extreme measures that include either replacing the lcd with a brighter one. or modding the existing lcd.... either one is pretty extreme, but I couldn't imagine my car without a pc
about the only easy thing that can be done is to remove the touchscreen overlay, that can help quite a bit, as it's the main cause of the glare.... past that you get into actual brightness issues that there is no easy fix for...