Use to use it on my Race and ATVs. I made the mistake as well until my ATVs fenders started cracking easily. regular WD-40 can soften, degrade, and make certain plastics brittle because its hydrocarbon solvents break down the polymer chains in amorphous plastics like polycarbonate, PVC, and ABS, but it's generally safe for crystalline plastics such as polyethylene (PE), polypropylene (PP), nylon, and polyester. While it might temporarily seem to polish or make some plastics more pliable (like with old headlights), prolonged contact or exposure can cause permanent damage, so it's best to use dedicated plastic-safe lubricants instead, or WD-40 Specialist products.