How to connect wires
When you retrofit items not originally fitted to your car, you often have to tap into wires or make new connections not already present in the electrical circuitry. The best way to do that is by soldering. Although making nice soldered joints requires a little bit of training and experience, it's still far from rocket science. Practice here doesn't mean months or years, much more like five minutes, especially as we're not speaking about soldering delicate semiconductor components on multilayer printed circuit boards but a couple of thick wires...