Water ingress

This model of BMW has had issues with the body plug mounted behind the passenger foot-well carpet area on the firewall. Pull back the carpet on the front passenger side and look for the body plug, pour water down the windshield and cowl area then look for the water leaking. You can either replace the plug or remove the body plug and put silicone on the sealing surface of the plug then re-install it. The rear passenger area will show signs of leakage because the front has better padding and will take longer to soak through. The body plug will look similar to #28 in the picture.

Hey TONES01,

Can you please check the rubber seals around the door aperture?

Any damage to the seals may point to a replacement being required.

If you find nothing here can you remove the rear passenger door panel and check the sealing of the door membrane?

If you run water down the outside of the rear passenger window does the water drain out of the drain holes at the bottom of the door or is it seeping in around the bottom of the interior door panel?

Check the drain holes at the bottom of the door are clear.

If seeping in around the door panel you will need to remove the panel and check the membrane.

The membrane should be completely sealed all the way around with sticky butyl rubber adhesive. If you have a leaking membrane it will cause the problem you are experiencing.

Regards, Joe