There is a leak "streaking" down inside car on inside firewall (under carpet) near central location at trans tunnel - leak goes down to passenger side of tunnel. Looks like it originates on wall (above plastic housing) rather than plastic housing that houses core and A/C parts. Is there any way to get at that connection befor housing. I've gone in at air intakes near windshield wipers - No access there. Thanks for any help out there.