Hyundai 2003 Sonata Owner's Manual page 7

A070A01A-AAT
CAUTION: MODIFICATIONS TO YOUR HYUNDAI
Your Hyundai should not be modified in any way. Such modifications may adversely
affect the performance, safety or durability of your Hyundai and may, in addition, violate conditions of the limited
warranties covering the vehicle. Certain modifications may also be in violation of regulations established by the
U.S. Department of Transportation and other federal or state agencies.
A080A01S-AAT
TWO-WAY RADIO OR CELLULAR TELEPHONE INSTALLATION
Your vehicle is equipped with electronic fuel injection and other electronic components. It is possible for an
improperly installed/adjusted two-way radio or cellular telephone to adversely affect electronic systems. For this
reason, we recommend that you carefully follow the radio manufacturer's instructions or consult your Hyundai
dealer for precautionary measures or special instructions if you choose to install one of these devices.