The header is probably not the production unit. It looks like the one used in the "Engine Run". It still has the bungs for the EGT and AFR monitoring.
I can't imagine they will be in the final design. Expensive to reproduce.
I don't now the diameter of the pipes, but they look big enough (AREA) for good gas/exhaust flow.
At least they included a "Heat Shield" around the radiator overflow? tank. Also looks like a closed system.
I could be wrong, but I think floydv was referring to the pic looking down at the suspension on the black Elio. You can see the exhaust make an abrupt 90 deg. turn to go back into the exhaust fairing. I kind of looked like part of the suspension when I first looked at it. Went back for a second look after Floydv mentioned the tight exhaust turn.