B-25J wing vents????

It's because of the difference in airflow behind the propellers, upward on one side and downward on the other.

Those are great photos! Thanks. Okay, that matches the vents on the model. Both vents serve the same purpose, so I don't understand why they look different. Now, should I try to open the starboard vent and possibly damage the wing, or just paint the inside of the vent black. Deep down I would like to open the vent, but I think lust painting it black would be a ssafer bet.

 Got this from Google walkaround, port side

Starboard side

I looked on google images of the real planes, the intake on the left wing is definitely less prominent as on the right wing. However, the port wing vent on yours is definitely wrong. Almost like a defect in the molding process. It does not look like what’s there on the real aircraft. I’d be modifying that if it were mine.