The caulking under the wiper motor seals out water from getting into the air channel - large square cross-section tube that runs across the car.

It is visible though the air intake grille below the windshield, especially if you look into the very ends of the grille to see beyond the ends of the baffle plate.

At the ends of the channel, it turns down inside the "A" pillar and then angles to horizontal to become the inside of the rocker panels.

The wiper motor shaft housing goes across that channel. Motor-to-channel penetration gets that black caulking. motor-into-cabin gets the rubber grommet. Water leaking into the channel would likely go on down the channel rather than leak though the grommet.

If, however, the channel has become fille/plugged up, water could leak most anywhere. Another place is to look at the 2-inch plugs on the inner side of the rocker panel. You will need to pull the passenger front carpet to get access. For me that always means pulling the passenger seat.

Once the carpet is peeled back towards the gear shifter, you will see two white plugs, look like little petri dishes vertical in the foot well outer wall. Pull one out and look inside (mirror and flashlight?) and see what's in there.

If it is loaded with composted leaves, pine needles, dead fauna, etc. well - there's your next project. You will need to pull all the plugs, front seat and rear, plus remove the panel with the lower seat belt anchor so you can get a vacuum cleaner nozzle in there.

I hope the solution is easier than all that.

Good Luck,

Bob

:>)