I think they can look good dependant on the car. Its a very rude boi thing to have though, just see them on little novas where they have got a neon on the underneath.
They arn't that expensive tbh, and not that hard to fit either, my mate had them and he had them connected to a switch, so he literally could just switch it on and off when he liked. Was quite cool actually. It's very "look at me". I have thought about them, but i think i would at least need a completed kitted car and i have literally done 0 mods to my car.