One problem related to underbody shield has been reported for the 2003 Mercury Grand Marquis. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Mercury Grand Marquis based on all problems reported for the 2003 Grand Marquis.
: the contact stated the splash guard panel underneath the vehicle that protects the radiator, power steering, and vacuum hoses, is very low to the ground and can be struck by objects in the roadway. Although a failure did not occur, the vehicle was seen by a dealer for inspection. The dealer was unable to duplicate the problem. . Splash guard always made contact with the bumper stop on parking lot, when a car pulled out the splashing guard made contact with it, making a terrible noise, the panel became more warped each time that it happened. Because it covered vital engine and steering parts, this panel should be straight and more secure.
| Paint problems | |
| Door Hinge problems | |
| Underbody Shield problems | |
| Body problems | |
| Structure problems | |
| Trunk Lid problems |