Move/change the backup lights to a strip of LEDs mounted on the diffuser, where the water holding cross hatching is, or on either side of the license plate.
Automatic temperature control.
Dual power front seats.
Longer visors.
Backup camera option for those who want it, possibly tied to larger multi-function radio/temp control/nav screen.
Standard short throw shifter. (who wants a long throw?)
Put a better feeling clutch in it. (SS at least....have not driven a V6 to know.)
A 1" drop, performance suspension upgrade from the SS level.
Ambient lighting across dash where it was planned, to match the doors.
Better, nicer floormats, with logo or something.
Put the loudest, best sounding mufflers that will meet the noise standards
from the factory, and have a "quiet" muffler option for those who want it. (It seems silly to put quiet ones on, and have thousands replaced immediately, for louder ones..........C'mon GM........... think of the waste.)
Factory painted stripes option.
It really needs to come with a nice portfolio for the manuals, rather than a plastic bag....
Just my 2 cents.