The car had 64600 miles on it and the headlights started going out while driving, which can be very dangerous. The problem is in the Light Control Module which is an expensive part (around $500 to $600 + labor).
2007 Mercury Grand Marquis Problem Reports
Most Reported 2007 Mercury Grand Marquis Problem Reports
The composite (plastic) intake manifold may crack near the thermostat housing and cause a coolant leak. Ford released an updated manifold that was reinforced to prevent a recurrence. No recall was issued for this problem but Ford did extend the warranty to seven years on some models from the date of purchase.
A spring in the seat belt buckle may wear or fail, causing the airbag light on the instrument panel to illuminate. Failed buckles will require replacement.
Transmission problems are common in this model, often as a result of a failed front pump. The pump loses its ability to create hydraulic pressure, which an automatic transmission needs to function. A sign of front pump failure can be a whine type noise.
The engine may overheat at idle when the AC is on. A new, upgraded fan motor and resistor may be required to correct this concern.
When it gets up enough speed for second gear it revs up and eventually catches and resumes normally.