Question about the Lights under your car

I had a little convo. with my friend on what I was planning to do to my car. And when it came upon the subject of lighting underneath the car. He told me it's illegal to use it on highways because it's kind of like having NOS in your car. Is that true?

I live in NJ.

depends where you live. depends if the bulbs can be seen.

the legality of having neons cannot be compared to having nos.
nos makes your car go fast.
neons make your car light up from underneath.

you'll only run into problems if you have red or blue neons because those are reserved for cops and ambulances.