There is a good chance it is coming from the drain plugs in the floor-pan. Jack the car up(use jackstands)and spray rubberized under-coating on them and around them. Allow 24 hrs to dry. It should solve the issue. The same goes for the boot and in the front footwells. There is another place that is prone to leakage in the boot as well. But you seem to have that issue licked.
133whp-126ftlbsTQ Eclipse CD8443,Eclipse PA5422, JBL GTO751EZ, PPI 356cs(Rebranded A/D/S 346cs), JBL p1024, SubThump enclosure, RAAmat BXT, Damplifier Pro
Hatch Nation #140
Caeci caecos ducentes