???Heater box
Same as mine ! Surely this should have been plugged? The engine is the other side and it must let water in ...I found the same hole in a TD5 last week. Even the mat was cut.hole goes through the bulkhead. Nothing to go there.
I told the owner it was extra venting
Was centre of the passenger footwell
As it was not my motor I was not worried.
Find the size hole & pop into hardware shop for a grommet