Will these bungee cords stretch out after repeated use?

These are engineered for durability across multiple load cycles. Over time, all bungee material relaxes slightly with use — inspect before each haul and replace any cord showing permanent stretch or fraying.

Are the hook ends plastic or metal?

Hook material and construction specifics aren't detailed in the product specs — verify with product images or contact support before committing to a specific application.

Can I leave these in my car year-round?

UV exposure and temperature swings will degrade bungee cord material over time. Store the zipper bag in a cool, shaded spot — your trunk works fine if you're rotating them in and out regularly.