This is exactly what I did. Left the fill adapter in and ran the car on my lift until the trans came up to the prescribed temp, then unclamped the hose and let the excess drain back into the original bottle. After which I put the drain plug back in mess free.My question is: why not just keep the drain port fill plug in the transmission with the ball valve closed after filling? (like this one: DAP # VAS6262 ) Once the transmission reaches the prescribed temperature you could open the ball valve and let the fluid drain. Once the fluid slows to a drip you could then swap it with the OEM drain plug and torque it down.
The only logical issues I can imagine with this are if the pressure in the transmission is high enough to possibly blow off the tubing from the fill plug but this seems unlikely since the DSG has an overflow vent. The second issue I could imagine is if there is a small window of opportunity between 35C and 45C temperatures where the fluid might not drain fast enough out through the drain port fill plug.
Don't take this too seriously, I'm just surprised the procedure is "try to be quick and not spill much" so of course I imagine myself bobbling the drain plug as all the fluid pours out
I just did my service and the engine was up to temp long before the trans reached 35 deg Celsius.
The temp requirement isn’t for the oil or the coolant, is for the transmission fluid. I used a my Snap On scanner which gave me the trans fluid temp, so no guess work and no need for OBD11.Oil or coolant? We all know the "coolant gauge" gets to 12 o'clock pretty fast, but true oil temp takes much longer. Gauge gets a woody probably before you crawl under the car . Just get a damn OBD11 and take the guesswork out of it.