[Riwright]

The clear/white zip ties are not intended for outdoor use. The plastic allows the sunlight to penetrate and destroy the tie.

You can get uv stabilized cable ties that will last longer. They are black. You should be able to get them at the hardware store. Don't go cheap, get the best you can find.

Some people use stainless steel hose clamps. These will hold up indefinitely. I don't think they are ideal in this application though. I would worry about road vibration causing the steel clamp to cut into the wire.