My priorities would be:
1: Open up wheel wells so that it has plenty of clearance for chains on all four wheels. I about died when I read that the chains shouldn't be used on half-tons and on the only on the rear of 2500s. What in the Hell were the designers thinking?
2: Level the Avalanche. Up in the front, for more clearance. Would look much better and would add to rear visibility. Kinda looks like it is getting ready for an enema right now.
3: Factory receiver hitch in the front.
4: Block heater standard.
5: Improve rear visibility and add rear sensors as a standard item.
6: Trailer witing in the rear bumper, not hanging down for us to scrape off.
7: Pin switch in the tail gate for cargo lights.
8: Rhinohide on bed floor instead of the heavy too-tacky rubber mat (that is a condenstion magnet).
9: General lift of about two inches.
Don't get me wrong, I love my AV, but some of these things are obvious design errors.
Steve