Hoping someone can give me good clue to cause.
My Piper Archer 2 leaks water into the floor pan via the rivetts in the floor nearest the rudder pedals every time it rains. Both sides do it though the starboard side is worse. As much as I have tried to find where it is getting in to date I have had no luck. I have had door seal checked (though it does not appear to be there as the carpet under door remains dry) and have silasticed around the windscreens. It is getting in between the floor pan and outer skin somewhere when the aircraft is parked. The outer drain holes appear ok also. Anyone else had simular problem and where did the water be found to be entering? Really giving me the sh*#s at present not to mention corrosion worries. Any help appreciated.

This may not relevant - but it is not unknown for water to get through the lapped fuselage skins; logically they're the wrong way around.

Not through the air vents?

Have you checked around the firewall's NLG steering rod area?

are there air vents/ wemacs, near the wet spot? are you closing them before it rains?

also, at least until you figure it out. can you turn your plane 180 degrees around for parking? to avoid wind driven rain.

also, sometimes you have to look far away for the leak as sometimes it leaks one place and runs along way.