the 2011 Audi A8 has a factory underpanel
And my 02 Infiniti Q45 has factory under panel for the first 38 inches.....just at the transmission.
also angled deflectors infront of the front tires.
there is a service panel that opens to reach the oil filter and the nut.
Had I not installed a full body kit which lowered the profile 2 inchs and created a gap to the panel, I would not have made a new one.