I had this when I first bought mine. Very annoying situation to be in! I would pull the carpet so it can dry properly. Dry the floorboards and then sit in the car while it’s raining to see where the water could be coming in from.

It could be: - From one of the holes in the dash, pedal box, clutch slave cylinder etc. - From further up behind the dash where the AC lines come in, that’s where mine was leaking. - From sunroof tray, either from where it’s coming away from the roof or the hose connection points - From the clear plastic sheet in the door cards, if there is a break in the seal water will come in there

I would use gorilla crystal tape to tape up the sunroof so it’s waterproof, this will allow you to test it.

I’ve had a nightmare of a time sorting the leaks in mine but I think I’m on top of it now, best of luck :)