As do many Buicks, Oldsmobiles and Pontiacs of my car's generation, the exhaust on my car hangs quite low now since the OEM rubber insulators have stretched to comedic parodies of their pristine selves.
And being that they are at the rearmost point of the exhaust, a little stretch there translates into a lot of drop. So I'm getting some new insulators to raise the exhaust and tuck it up underneath the car like it left the factory. A bonus is additional ground clearance.
I wonder how much aero gain I'll get from restoring the factory exhaust drop. The underside of my car is pretty smooth except for the exhaust hanging down. Likely not much, but dragging lengths of 2.5" pipe in the air underneath the car can't be good.