[soundman98]

The law is very grey in that area. Legally, if someone rear ends you, they are at fault. But also legally, any tail lights that have been altered from the way they left the factory(only the manufacturer of the tail lights can certify they meet DOT specifications) are illegal to be on the road.

I don't know of any precedence in a case like that, but if the person rear ending has knowledge of it, it would likely make for a long and drawn out court case for arguing that the altered tail lights were the root cause of the accident in the first place, making the lead car at fault.