Behold, US Regulations at their worst (ok, not worst, but god awful).

As you can see from the image above, the rear end of the Bugatti Chiron is quite a sight to behold. With vast mesh expanses, lashings of carbonfibre and one gigantic light bar, it gives the Chrion’s bum a striking aesthetic. An aesthetic which is enhanced with two massive lumps of rubber on US-spec cars.

https://www.carthrottle.com/post/the-bugatti-chirons-us-spec-bumper-is-moderately-upsetting/