You should lower your car for preferably 1.5 inches. This is the finest height to have the aggressive lowered look and still it is in comfortable come ride. If friend go even lower, the ride will certainly not be stiff, you have actually a high threat of bottoming out and also scraping versus any driveways and also speed bumps. 

By the way, bottoming out happens once the bottom that your vehicle hits the road. In case you no know