A 1/2" offset isn't going to do much at all. With a 3" relocation you'd probably need higher rear spring rates or a larger rear sway bar, but for a 1/2" it's not going to make a dramatic difference. Might be helpful to have an adjustable rear sway bar or shocks, as you could alter the settings slightly to make up for the offset. But you'd have to really be flogging the car to notice. The width of the tires and extra grip would have more of an effect.