Installing interior car lights, whether neon or LED, is a great way to customise the interior of your car. You can install interior lights at the bottom of the dashboard to illuminate the floor for front passengers, underneath the front seats, to illuminate the floor for rear passengers, or for convenience in various parts of the car, such as the map compartment. Interior car light installation is relatively straightforward, but requires involved electrical wiring; if you lack experience with electrical wiring, consult an experienced electrician before beginning.
Turn off the car battery before you start working on your car.
Find a convenient place in the interior of your car to install your lights, away from where they can easily be kicked, displaced, or damaged. Mount the tubes on the car structure, according to manufacturer's instructions.
Connect your interior lights, following manufacturer's instructions, to the "toggle switch" that controls your lights, using the 12V power wire.
Use 12V power wire to connect a fuse less than 18 inches from the positive terminal on your car battery. Solder the power wire to the fuse, using a soldering gun.
Connect the fuse, using power wire, to the toggle switch on the interior of your car. Pass power wire, connected to the fuse, through one of the existing holes on the firewall of your car, which separates the interior compartment from the engine. Connect it to the toggle switch, per manufacturer's instructions.
Complete the electrical circuit by connecting the ground wire from the interior lights to solid metal of the car chassis. The easiest way to do this is to attach the wire, using electrical tape, to bare steel under the dashboard.