Can you adjust the air suspension ride height on a 1999 Grand Marquis?

Not meant to be adjusted, so not easily adjusted.

It is true that the ride height is not meant to be adjusted, but that doesn't mean that it CAN'T be done.

Above the rear axle, attached to the body of the car is a switch that looks like a small shock absorber. The end attached to the body can be adjusted by moving the mounting point. I would not recommend doing this. Small adjustments to this bracket or the switch could cause a failure of the air ride suspension, and could cause serious injury to people in the car if it failed while the vehicle is in operation.