Brake Sensor problems of the 1996 Mercury Cougar

Check for coolant leak at intake manifold. Replaced intake manifold. There were regular oil changes and tire rotation. The engine light had come on, and the coolant light would come on and off. The dealer had to replace the engine sensor light and added a cup of water. The consumer's son in law was driving the vehicle and white smoke coming from under the vehicle, the rubber strip on the inside of the vehicle was coming off, the right rear trim panel coming loose, the brakes made rubbing noise intermittently, glove box door won't shut, the air bag would rattle, the right front door rattled while the vehicle was in motion, and the door switch trim panel was discolored.