Most insurance companies will not cover vehicles that have been modified, altered, restored mechanically or structurally which results in a change in performance or appearance including any raised or lowered chassis. If you have simply added a 'body aerodynamics kit' than your premiums would not increase nor would your vehicle be unable to be insured. In addition, any special equipment or customization to your vehicle would not covered unless added by a specific endorsement.

You can get a car insurance quote here to see how much it would cost to insure your car.