Wire holders

Totally unnecessary. If your insulated wire rattles, the panel is rattling.

I use the plastic ones. They give a bit and won't interact should they manage to cut through the housing.

When you have a DSP unit, 4 amplifiers on an amplifier plate as well a 2nd battery, wire management becomes necessary if you want to keep everything organized. It also reduces the pull on the connections on the devices to almost zero.

Many people draw out their wire paths and drill holes on opposite sides and then use zip ties. I like those clamps, cause they're easy, look clean on wood or carpet and you can remove them and put them back should you need without having to pull the plate out.

Keeps things neat and tidy!

This is what I ordered from Amazon.