2000 Ford Taurus Popping noise while driving?

Have a popping noise while driving, typically i would expect something simple like ball joints, tie rods, cv axle etc. But its at an odd time, its randomly while driving straight, no bumps or anything. It kind of sounds like something is hitting the underside of the car like a chunk of mud. Any ideas? Ball joint are new and the axles don't pop or make noises when turning. Someone suggested the engine mount on passenger side. This is the DOHC variation.

Why is my car doing this? - 1

When i have the car 1994 ford taurus jacked up, if i spin a wheel clockwise the other wheel turns counterclockwise.

Added (1). Sorry i forgot to mention that is is the front wheels that do this. The car does not roll at all when it is on the ground.

Ford Taurus 03 driver side leak after rain, Not coming from the A/C, door, or windshield. Only floods after rain under carpet! Any ideas?

Ford Taurus 03 driver side leak after rain, Not coming from the A/C, door, or windshield. Only floods after rain under carpet! Any ideas?

Added (1). Floor seal is good and not torn, I did put the garden hose on the windshield but there was no leak observed. It seems that the leak is found only after heavy rain and it is right in the middle of the driver side floor so it is not coming from the door most likely since the area near by the door is dry. It starts with getting wet right in front of the peddles. No signs of water leak on the inside of the firewall