Lots of water in both footwells

[Racer75]

My car has been sat up for a couple of years now and seems to have developed some leak.

Both footwells are underwater and I have no idea were its coming from. Is there a main culprit that causes this? I have had water in the passenger side (UK car) and no elephant trunk drain.

Doubt its the heater core as the engine has not been run.

I have also destroyed the little floor seals, so if anybody knows where to get them it would be appreciated.

Cheers