Should be normal to have negative camber, lowering springs or worn out springs could accentuate the lean. However, when you set the car down, the tires are stressed while the suspension is trying to re-establish that normal amount of negative camber. When you roll the car after setting it back down, that allows the tires to untrack their freshly set down positioning and when that happens, the negative camber comes back. Do you enjoy fast cornering? That negative camber helps the car track well during moderate body lean experienced in cornering. Is the car a sport model? The rear sway bars are the same, but a sport has a 30 mm front sway bar which reduces the ability of the car to lift up as much on the inside of the side of the car you are turning toward. I never drove an LS without the 30 mm sway bar, but if you can stand behind your car and picture the car in a turn with that side of the car lifting up, the other side of the car will appear to neutralize that negative camber and the wheel would appear to be standing straight up, instead of negatively cambered. This is one way that the negative camber helps you turn hard with confidence (considering tires are in good shape and inflated properly.)