I've noticed that my driver and passenger side carpet is constantly wet, I have weather tech mats and have tested the "water proofness" of them, they don't leak any water. But I'm noticing that the underneath of the mats are wet along with the carpet but the top side of the mat is dry and has been for some time, which tells me the water is coming from the bottom. Its getting to the point where the wet smell is becoming a problem.

I have the panoramic roof, anyone know of any drains that could be clogged that would cause water to drain on to the driver / passenger sides?

You'll want to keep your MB away from rain or any car wash BEFORE it develops pronounced electrical troubles.

It has multiple ways to leak insides...:

1. roof drains
2. roof seams
3. windshield seal
4. cawl overflow

^agree

You have a leak. Fix it. Water will damage the electronics under the carpet and then your problems get worse.

5. Heater Core (very rare)

heater core is a sort of luxury special:
you get a complementary steam bath with foged up windshield -
Very classy

Leaking heater core would probably have a coolant smell inside.

May want to check the evaporator drains under the dash, on some Mercedes there are bulletins about them coming undone and water leaking onto the floor.