Stretch a pair of tights over the light? Or go 'au naturelle' would be my preference.
Saw that on a 'cops on cam' prog. They pulled a guy over & made him take the tights off, he had to make a bit of a mess of them to get them off the lens.
Tights on ya lights! Done it before, just stretch them evenly. Looks tinted, full amount of light when illuminated