I am trying to use Kool-It to clean the evaporator and the instructions is from the evaporator drain under the car.
https://www.lubegard.com/products/koolit-evap-cleaner/
Does anybody know where is the drain on E320-2008?
Thanks

moved to W211 forum...

Its above transmission.
MB unique design that condensation evaporates on hot transmission, so you don't leave puddles around.
But I guess that makes it unusable for your purpose?

Or you could access through the evap temp sensor under dash on side of hyacinth case

Sorry hvac