One problem related to door has been reported for the 2000 Mercury Cougar. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2000 Mercury Cougar based on all problems reported for the 2000 Cougar.
The door locks installed allow the driver to hit a switch on driver's door to lock passengers, or to push in the lock, which will lock both driver and passenger's door. Upon entering the vehicle I have pushed both the switch and lock, neither of which would lock the passenger's side. I repeat this up to 10 times before the passenger side will lock. Not too safe!! 2nd complaint---stereo will be on and the driver's side speakers will shut off for a few seconds and you will only hear passenger's side. Then they will come back on. This happened every 10-15 minutes for about 3 monthes but has not happened in a while.