I see the Zee as being a disciple of "minimalism"...less is MORE.
*ZL1 splitter/spoiler (aero-correct), with perhaps (since the Zee is a "heritage"-based Model) the Heritage Grille as an identifier.
*ZL1-type forged wheels/rubber for gription and lighter weight
*Perhaps a lighter, heat-dissipating/vented hood
*A few badges, grille/rear/fenders
I don't think the price-point will afford the rear brake ducts that could replace the "vents", although GM PP would be remiss if they didn't offer 'em as a GM Accessory.
Call it a day...
NO GRX etc...nothing without merit and value that might otherwise add unnecessary weight.