There's a
unique aero duct for the ZL1's transmission cooler, and indeed there are no less than 11 special coolers for various mechanical
bits in this car (notably the differential), a little reminder that heat is a potentially destructive byproduct of extreme power and speed.
I guess I had the 2002 - 2006 (2007 Classic) Sierra Denali in mind, which had a
bit of body
aero trim in addition to a different grille shape,
unique headlamps, it's own two - toned interior colors and
unique interior trim.