Also, I'm wondering what specs people are running that do track or autox. Specifically wondering how much negative camber to have on the front tires.
What works best depends on your set up, based on a myriad of factors. Just one example is the difference between 18's and 19's. As the factory specs indicate, 18's calls for a bit more -ve camber than 19's. Actually, it has less to do with the wheel diameter than what tires are typically mounted on each. For the Stinger, 19's tend to get lower profile 40 and 35's, which have less compliance and, therefore, cannot conform to the road surfaces under cornering load as readily. Too much -ve camber on such tires would cause more stresses on the inside of the tire than the outside. For track performance, you want to maximize grip, which means even load over the entire width of the tire, under cornering forces, in a cornering attitude. 18's typically get higher profile 45 series tires, so more compliance means more tire deformation/deflection under extreme cornering forces, so a bit more static -ve camber compensate for that. HOWEVER, if I mount 35series tires on 18's, the car would likely work better using camber specs more inline with those generally regarded as optimum for 19's. In fact, my next set of track tires might be 245/35R18 or even 255/35R18.
Another factor is whether you have stock suspension, lowering springs, coilovers, and/or anti-roll bars. With stock suspension, Body roll when cornering and dive/squat when braking/accel'ing will be quite substantial. On the one hand, a bit more -ve camber up front will help reduce initial understeer, but the stock geometry's inherent camber gain when the front suspension articulates will naturally dial in more -ve camber when the car body rolls on hard cornering. Stock suspension, of course, has no camber adjustment up front, so you get what you get.
If you're on moderately lowered springs, your front static camber will be slightly more -ve, which helps reduce initial understeer, but once you roll into the corner, the same camber gain stock geometry is there so not a whole lot different than at stock ride height. The main benefit is the lower CG reducing the amount of weight transfer, when the chassis gets tossed around.
IF you are on coilovers with adjustable camber plate, then that opens up tuning possibilities a great deal. If you don't know how to dial in suspension, get somebody that knows how. I would caution again excessive amount of lowering, IF you goal is track performance. Stinger's suspension is designed to work best in the stock configuration at stock ride height. Lowering a small amount has the benefits mentioned above, but too much can be bad. With MacPherson struts, the -ve camber gain only happens for a limited amount of initial articulation, beyond which that -ve camber gain will transition into +ve camber gain. Losing -ve camber is very bad when cornering at the extremes. So DO NOT be tempted to set up your suspension based on what "looks great". Static camber is just that... Static. Your car doesn't go around the track on static camber, so how camber changes dynamically needs to figure into your static camber setting decision.
Also, maximizing cornering grip still needs to be balanced with maintaining straight-line braking/accel'ing grip. The latter obviously favors zero camber angle at full thrust (brake or launch). So... goes to show you that EVERYTHING is a compromise. There is no free lunch.
The above is just scratching the surface of suspension tuning. If this makes your head spin... well, it should. Suspension tuning is a great deal more nuanced than most folks realize. I myself find it orders of magnitude more fascinating than engine tuning, and the end result of "getting it dialed in" far more satisfying.
