They believe it's a silver Mitsubishi Eclipse, which should have bullet holes and might be missing a passenger side mirror. From Joe Lambe:
Overland Park police said today that a car involved in a fatal disturbance between the occupants of two cars may have bullet holes in it.
As two cars sped down U.S. 69 on Sunday, shots were fired and one car lost control and hit a light pole, killing Marquise Williams Jr.
The other car, thought to be a silver Mitsubishi Eclipse, drove away. It may not have damage to the front as previously reported, police said. Besides possible bullet holes, it could be missing the passenger side mirror.
They ask anyone to report such a car to the TIPS hotline at 816-474-9477.