Water still leaking on pass floor after windshield seal replacement (I searched)
 

The car is an 87 coupe that I just replaced the windshield seal on. The car would leak significant amounts of water on driver & pass floor. The old seal was definitely shot and the new one (factory) looks to be very dry. After recent rains, water is no longer being found on the drivers side floor - but just as much water as before is still getting in onto the passenger side floor....? My question after searching is - should my focus be on the sunroof seals and vent drain (in smugglers box) only. I didn't find any other possible locations for leaks in several searches. thanks!

i had this problem caused by the door seal actually.
(I got no sun roof). I simulated rain with someone hosing down the car at various locations.
I would isolate the application of water point to point. Meaning don't just have someone spray water everywhere, but have it applied at the suspect places, whilst u sit inside the car and observe for water ingress at that part.
I come from a tropical/equatorial country which sits pretty close to the equator.
So imagine the Heat & Buckets of water that we get as climate.

i suspect that the replacement rubber seal is not sealing well. i think ive read threads here about people replacing old rubber with new, only to have leaking continue. as you said, your replacement looks "very dry"....

thanks guys! all good info. and I agree just because the new seal 'looks' dry - it may still be the source.

For whatever its worth, I had a water leak on the drivers side of my car. I had the sunroof drains cleaned out and I haven't had any water leak in since.

a good way to clean out the sun roof drain is to go to a bicycle store and buy a long brake cable..use the metal cable (without the plastic sleeve) and insert it into the drain tubes along with some WD-40...see what comes out.

what worked for me
there are rubber gromets near the hindges when you open the door .I think it is where the speaker wires go . look there

Just found and fixed the front passenger floor puddles in my 911. Looked everywhere, and found the problem with the hood seal! The upper right hand corner of the seal had a split in the 90 degree corner. I found the leak by flooding the windshield from the top with a garden hose. Don't spray, just flood like a rainstorm would. After the "flood" I opened the hood and saw water pouring into the trunk and puddling right by the big hose that goes down thru the bulkhead to the heater input. I pulled back the carpet, and the water was dripping down along side the hose to the floor. Fixed hood seal and no more leaks!

Check to be sure the drain hose from the fresh air intake is connected, doesn't have hoies, and drains out the bottom of the car. You can check this easily visually (remove the cardboard blower) and then also by pulling back the passenger's floor mats and pouring (a little) water into the fresh air intake. If the hose is the problem, you'll see water running down wires or through the under dash air vent into the passenger's side foot well. I had this problem also after a windshield replacement. Its a simple fix and I've posted a thread with materials listed and photos. Search for my name.

Let me know if that's it and if you have any questions.

David