GTA_Driver

They break in places with heavy snow fall. Backing up will collect snow and eventually they break.

There is definitely a difference in road noise. When my broke on the C5, I could hear wind whistle at highway speeds.

bigshotking

Well yeah, one of the main reasons for the belly pan is to keep objects from flying into the engine bay and cause damage to the engine. It also helps with aerodynamics and cooling the transmission by directing air around it.

Just Me

my guess is mainly aero and cooling....