Reflective Lightsaber Windshield Wiper Tag
Seems to me that waving around a lightsaber in the rain would make you go Schvrmmmmmmm-shish! just like they do, but I guess WiperTags has taken the necessary precautions with their Star Wars-themed WipeSaber windshield wiper covers to ensure cars sporting them stay electrocution-free. Like, for example, they made the lightsaber tags out of reflective decals rather than charged electrical parts.
The WipeSaber wiper covers glow in reaction to faceoffs with headlights, streetlights, or other bright lights. They are 16" long, so can attach to most rear windshield wipers regardless of blade size. WiperTags says the lightsaber decals are laminated and UV-protected to maintain their adhesion and Force-compliant aesthetic all year long, in all types of weather. But you should remove and reapply them before / after entering a car wash.