I dont understand Japanese but it appears to be about suspension and wheel fitment.
One thing I'm sure of is the Z looks amazing in black and I am glad it gets wheelhouse liners.
That means it won't sound like coins in a dryer when it rolls over the slightest bit of gravel.
Anyone know what this is?
It can be seen at the 6:40 mark.
Edit:
I found out its for toll collection on Japan toll roads.
https://andrewsjapanesecars.com/what-is-this-box-card-reader-etc/