To give your scale windshield a top tint, use Clear Blue acrylic, slightly thinned. Carefully fog the paint over the top quarter of the windshield. Apply light coats to avoid runs and consequent dark spots. Several thin coats work better than one or two heavier coats.

Once you are comfortable with the shade of blue, let the paint dry overnight. Acrylic dries as hard as lacquer if left alone for a bit, so give the paint time to dry completely.

When dry, use some metal polish to smooth the surface and eliminate overspray. Follow up with plastic polish and a soft cloth to shine up the windshield surface.