My guide to replacing a classic car windshield and finding the correct glass specification, because the windshield affects both safety and the car's visual character.

Modern safety glass has a green tint at the top edge — the band-shade. Original windshields from the 1960s and early 1970s used a blue-green tint or a grey tint depending on the manufacturer and year. The color difference is visible and affects whether the finished car looks correct.

The glass thickness specification matters too. Aftermarket replacements vary in thickness and the difference affects how the glass sits in the opening. A glass that's too thin will rattle; one that's too thick won't seal properly.

For concours work: source original-specification glass from a supplier who documents the spec. For a driver: a quality aftermarket windshield is adequate, but verify the shade band color matches the original.