Smell of antifreeze in cabin.

[Blacklab467]

You'll need to disconnect the battery if you are going to remove the seat electrical connectors underneath the seat.

[dikidera]

A small update, though it will take a while to verify.

I noticed the hose that goes to the ECM fan was wet. Further inspection revealed that maybe just maybe the hose connecting to the coolant tank was maybe leaking, and I did replace that exact hose right around the time my problem started to appear. The ECM fan hose goes to...you guessed it, right inside the cabin. If coolant was leaking onto the hose, it's made out of some insulating type of material but is not waterproof, no wonder I was getting a strong smell in the cabin.

I tightened the hose clamp more and re-filled coolant.

But

You guys have given me food for thought and I will also have to inspect all the carpets now in the very near future.

[vtl]

You may need to replace the expansion tank, it eventually develops leak around the hose.

[dikidera]

It is indeed still leaking...

[Blacklab467]

You might find that the carpets are wet on top and dry underneath if this is the case which would be a bonus. You'll have to remove them still to determine this and if the front is wet then the back will be also. At least you found the definitive source of the moisture.