I did this on my DC4 using some cheap ass $10 LED bars from Wal-Mart. No guide or anything. I just got creative and shoved the exposed wires into the connector for the light in the glovebox. Only turned on when I turned on the park or headlights. Didn't cause any problems, and the last time I saw my friend, they still worked. I had to replace the drivers side one twice because I pulled a wire or tapped it with my feet, lol. Didn't use any relays or regulators or anything and it didn't mess up the battery or anything else electronic since they were only 12 volts and 2 LEDs on each bar. This was the only thing rice about my car, but I didn't care.
The very first time I connected them, a wire got loose, and when I tried to put them back in the glovebox connector I ended up blowing a 10A fuse somehow. No interior lights and no park lights til I replaced it LOL.
I thought about doing it to this DA(it has no interior lighting besides the radio and gauges), but I'll be having that white car back soon. Hope they still work. Maybe I'll wire up a switch for when I wanna go stealth mode or somethin hahaha. My windows were dark but you could still see blue when you got near the car or looked through the windshield.