Positives
1. Most Stanced cars are low cars and low is cool and streamlined.2. Stance is also called camber. Negative camber is stance. See picture below
Positive camber is like like lightning McQueen when he's doing a jump.
Negatives
1.Sometimes if your car is to low and stanced you are unable to drive over speed bumps or get onto your driveway.2.Stance isn't always good because it wears out the corners of the tyres and damages the rims.
Most people get expensive rims to look good and you do t want to damage that!3. Also if your car is to wide or your wheels aren't covered properly, your car might not be road legal