Charles the only way to dry the carpet is to lift the wet side footwells
If you can't take them out completely or soon enough the car will smell musty !
Carpet "may" appear to dry up from above.
But the mould and rot will set in soon enough unless the foam soundproofing is completely dried out underneath. 2 inches thick and holds gallons !!!
If you don't want to remove carpet completely, then lift the affected side of the carpet (remove trims etc)
Place several dry towels under the wet foam and let them soak up the moisture. (car can still be used as long as pedals are not fouled with anything)
Repeat this process each day for 10 days !
Carpet will then be approaching 90% dry.
There's so many 75's about now stinking of mould
If water is found in a front or rear footwell carpet, there will be gallons sitting in the foam sound proofing underneath which is 2 inches thick in places.
If front RH footwell is soaked then the Rear RH will be also.
Water travels front to back or vice versa. (it cannot seap left to right because if the central floor pan tunnel)
So a RH boot leak for example can end up in the RH front footwell after the car has been parked downhill.
Remember water will always find the lowest point.
If you are unlucky enough to have wet LH and RH footwells, there will be 2 or more leaks to trace .
Look for witness marks like a limescale trail if the leak has been there for a while.
Known places for 75ZT leaks are:
Lower Plenum drains blocked, water enters via the pollen filter into heating ducts.
While oval scuttle clips below windscreen.
Missing grommets in bulkhead.
Front sunroof drains come adrift.
at bulkhead. Duck bill ends blocked which need cutting off.
Same applies to Rear sunroof drains. Water enters the boot.
Rear light rubber gaskets split.
Side trims on rear wings.
(2 holes behind each trim need sealing with silicone from the inside)
Cabin exhaust ducts in boot below carpet level. (Seal round edges with silicone)
Rear bumper removal is the most effective as these vents need sealing from the outside.
Drying out process:
Dehumidifier will be futile I'm afraid!
If removing carpet is too big a job for you I suggest lifting the carpet edge up
and use 2 old towels, one under each footwell.
Allow them to blot the water up and then hang towels to dry.
Repeat this about 20 times and the undercarpet foam will then be reasonably dry.
Make sure you find the source of the leak otherwise you'll be back to square one!
Good luck
Jules
PS for Arctic
Steve it was some of the very early cars which had a separation in the plenum area
