Missouri laws have become a bit relaxed...
In Missouri, this percentage refers to percentage of visible light allowed in through the combination of film and the window.
Windshield Non-reflective tint is allowed along the top of the windshield above the manufacturer's AS-1 line.
Front Side Windows Must allow more than 35% of light in.
Back Side Windows Any darkness can be used.
Rear Window Any darkness can be used.
HOW REFLECTIVE CAN THE TINT BE IN MISSOURI?

Similar to sunglass lenses, some tinting film contain metallic elements that help in reflecting incoming light and reducing the glare and heat generated by visible light.
Front Side Windows Must not be more than 35% reflective.
Back Side Windows Must not be more than 35% reflective.
Restricted Colors No colors of tint are explicitly banned.
Side Mirrors Dual side mirrors are required if back window is tinted.
Certificate Requirements Manufacturers of film do NOT need to certify the film they sell in the state.
Sticker Requirements No sticker to identify legal tinting is required.
Medical Exemption State allows medical exemptions for special tint. For more details about the specific terms of the exemption, consult your state law.
Getting a Medical Exemption is extremely hard in the state of Mo.
Check out
www.tintcenter.com for more states information.