This is the third time this has happened. Last night while i was driving home it started to pour down rain. i get home, park the car and walk inside. this morning i decided to clean out the interior of my car. after removing my floor mats i noticed that the carpet in the drivers area was soaking wet

. none of the carpet in the rest of the car was though, just the drivers area. i checked all the drain plugs to see if maybe one was loose or gone and theyre fine. There are no leaks coming through any part of the firewall or the door either. honestly im out of rational explanations for why this occuring. i drove home on city roads the whole time and dodged all the major puddles in the road. does anybody have any idea or explanation for me?
by the way i drive a 98 SR5 4x4 and i have husky liner floor mats throughout if that makes any difference. thanks in advance