The Irish have a word for this: Diffin! These bosozoku are diffin that R31 Skyline together with some of their friends on a small stretch of road at a random meet.
I have no clue what the official Japanese word for diffin is, but it surely must be something cool! 😛
I’ve seen many parts swapped on various different zokushas and by far the tail light swap is the most popular. For instance: on this normal looking 280ZX you really wonder why it is featured as a zokusha:
Nissan 280ZX with swapped tail lights
But at the rear it is a totally different car:
Nissan 280ZX with Skyline C210 tail lights
Personally I’d favor the C210 tail lights! 😛