Splitter Guards- ZL1 Addons sell these. Machined aluminum guards that screw into the bottom of your splitter. They work. You'll hit these before your splitter gets ground down. Well worth it and easy to install. I also bought their Heavy Duty Magnetic Jack Pads. Another small investment to make life easier and not destroy your chassis when jacking the car.
Heritage Grille and Flowtie
I did a write up on this here:
http://www.camaro5.com/forums/showthread.php?t=367071
I originally modded the Bowtie that came with the Heritage Grille (GM Part# 22965834), but I later found a genuine Flowtie.
My best cosmetic mod
See the pic in Post #9 above^^^^
EDIT: I've received tons of requests for me to sell my modded Flowtie, but sorry, my son owns it now!
Fluids and Gold Plugs- Lots of feedback from members here about the sometimes unfriendly TR6060 transmission. I drained the ATF from the trans @1600 miles and added Redline D4, took just a little under 4 quarts.
Also drained the rear gear lube @ 2300 miles. WTF! Wow, nasty sh!t. Added Redline 75w90 #57904, took 1 quart and I added GM Limited Slip Additive part # 88900330
I added Gold Plug Drain/Fill Plugs to the rear (# AP-07 need 2), and trans (IP-04X, need 2). I picked up one for the engine at AutoZone, Needa brand, M12-1.75 (# 653096). Just a little more protection as they have a strong magnet within.