if the windshield has been replaced look in the lower corners under the weatherstripping for rust holes ,this will cause wet front carpets also.usually happens because window installers do not treat chipped/scratched paint caused by windshield removal.also look in engine compartment against firewall for front cowl drains (look like elephant trunks )and make sure they are clear or water will back up in cowl and leak onto carpets

Cleaning car from winter. When I went to vacuum floor, the front floor carpet is wet. Drivers side is soaked and passenger side is a little wet. Are there drains that I can check for? I will put car on jack to look for rust but have not noticed before.
THanks
JD

I had the same thing on my M3, first check the drain tube on the engine bay bulkhead above the manifold, then remove the black grills on the scuttle panel and clear out any crap. on my car the drain tube was blocked and water was collecting in the scuttle and built until it leaked past the heater motor( bolted to the scuttle panel)i also had water coming in via the steering column grommet. hope this helps