I attempted to apply some ATV sealant around the air vent box but that area is not really accessible. The wiper arm stud plate is spot welded on; saves two bolts which would have been more expensive than the spot welding. I remember me Dad telling me that Ford was bad about leaving out bolts to save money but GM may be just as bad LOL. Even if I attempted to remove the wiper actuators out of the way that plate still prevents properly sealing the area. I used my fingers and got it where I could reach. I noticed that caulking at what I am guessing is a seam had cracks in it so I smeared ATV sealant on that as well. I will let the ATV cure out and then do a water test. It might not even be the air vent. However, I can not remove the dash to try and track down this water leak so may have to live with it.

Good luck, keep us posted with what you find out, hopefully it won't leak anymore, if it does you may want to consider getting a giant tarp and covering the car, it is what I had to do before, and if I cannot trace down and fix my leak(*) then I may do the same once again.

I have not stopped the leak and I spent most of the day on it. I noticed wetness along the area where the wheel well is meeting the firewall. I think the water is seeping up through that seam. Inside the car the water is coming down from up under the dash and trickles down to the footwell. I think I will take the vent cover back off and inspect that area near the driver side again, I noticed cracks in the caulking so maybe I just need to apply some RTV to the area. I noticed in my past comments that I said ATV; I meant RTV.

One little trick I use to find leaks: I use an aerosol w/* cleaner that foams up...in your case, I would remove the plastic cowl under the wiper arms and spray the foam in seam areas.....then from the inside, I use an air hose with a long nozzle, so I can shoot air in the approx. area where I think the leak is on the inside, and have someone watching on the outside to see if the foam bubbles up or blows out.....a strong soap solution works too.....

Thanks for the tip. We have rain moving in for the next two days; I am sure the inside of the car is going to get wet again. I may see if I can pick up a huge tarp tomorrow to cover the car.

If you get a tarp go for an extra large one, I got one big enough that I was able to tuck it into the wheel well/over top the tires, this kept it from blowing away when it gets windy, just remember that if you have been driving the car for a while, give the brakes time to cool down, as once I noticed the tarp slightly melted in one area.
Of course you could use bungee cords to hold it in place, if you have any of them.

Your cars length should be 16.6 feet long, and 6.1 feet wide, of course you will want it a good bit bigger than those dimensions, as you want it to come down over the car at least to the wheel wells, a tarp that big won't be cheap, expect to spend around 50.00.
If you have a Harbor freight store in your area they may have one for around that price, I did not have one nearby so I ordered mine from a site online, cannot remember which one though as it was a long time ago.

Just looked, and I found one for a bit cheaper, it should be plenty big enough.
11 ft. 4" x 23 ft. 4" All Purpose Weather Resistant Tarp

if you care about your cars paint i would put something to protect it from scratches between the tarp and the car

Good tip Justin, I was going to mention that, I actually typed it out, then deleted it, as I figured the possibility of scratching the paint was common sense, I of course have a special paint job that cost me around 1,300.00, but I was careful when putting it on, and taking it off.
They could always go for a more expensive actual car cover, but unless you get a really good one, I am pretty sure some moisture can work its way through the cover, I guess it all depends on what cover you get.

what i did if i left my car out was get a cheap cover from walmart, because like you say they are almost all breathable ones and then put the tarp over that

Very good idea Justin!