Car - AE86

motor - 4ag

use - Daily

problem - Leaking water into drivers foot compartment

occurs/started when - It rains? Can be parked and it still leaks, so not driving related.

personal situation - Annoyed

Water is running down the foot pedal area and collecting in the drivers foot well.
Initially I thought it was the lack of floor plug, but replaced that, and used seam sealer and it still leaked.
I have the feeling it is running through the join at the firewall join to the vent opening area?
I have run water down that region, and it seems to dribble a little bit down inside, but it may have just been residual.

So, next I am going to put talcum powder on the inside and flush water through that area to see if it displaces the talc.
Now, what should I seal that seam up with? Generic seam sealer, and just place a fillet in the region?
I watched an AE86 hot version vid at some point and they replaced the seam sealer on the door gutter region (roof join) with a white sealer in a silicon type dispenser tube.

Does anyone know what the product is, and will it do the trick?

The car is in pieces, the bonnet removed, lower windscreen shroud, front drivers guard removed, as I will be re-sealing up the front wheel area while I am at it.

It has been raining quite a bit in Adelaide, and has got to the point that I am sick of driving with wet feet and goldfish.

Any ideas, or recommendations on where else it may be coming from would be greatly appreciated.
Thanks.