Can a sun-faded, whitish dashboard be restored?

Often yes, if the plastic itself is not cracked. Whitish or chalky patches on a dashboard are usually UV fading of the surface, sometimes combined with residue from cleaners. Clean the area with a diluted interior cleaner and a soft brush first, then apply a protectant or coating made for interior plastics, which darkens the faded surface and adds UV protection. Choose a matte or satin finish to avoid windshield glare. Cracked, sticky or soft-touch surfaces that have broken down cannot be fully restored and may need professional repair or replacement.