The floor on the driver side in the front and back seat of our 1998 Toyota Camry has become drenched every time it rains (which is not that often where we live in Southern California). Any ideas on how to remedy this?
Does the car have a sunroof? If so, the drains could be clogged.
Another possibility could be a door seal rubber that is not fitting correctly due to a seal fault or a sprung door that is not fitting correctly. The latter can be caused by opening a door or the wind catching a door too firmly or a collision repair.