I really wish I thought of this and did this sooner. Having the ability to control 12 V accessories with a remote control and not have to run wired it’s a brilliant idea I do say so myself.
The 4CH RF Relay Wireless Remote Control Light Switch is a must-have to control 12 V equipment easily and effectively. This unit has 4 channels which means you would have four separate switches, and they also offer 6 and 15 relay switches.
Think this, versus needing to run a cable through your car’s firewall to a switch in the car’s cabin, you would tap into the fuse box under the hood for a 12 V source, then wire up your accessory to a channel model, and you are ready.

Wiring up each channel was pretty simple, and I attached a wiring diagram for each channel below. Let me know if you have any questions.

The remote is small and discreate with a sliding cover to protect the buttons when they are in your pocket.
Right now, my exterior LED lights facing the rear of my car, Air compressor, and Wifi LED lights are each controlled by the remote system.