I did a few searches in this forum to see if there were any posts on towing an ML350 4 down and could not find one. Anyone out there doing it and if yes what equipment are you using ?
The manual does say the GL can be towed 4 down but doesn't say for how far or how long. I know there are some limitations on some cars such as having to start it every 500 miles or so the lubricate the transmission. the mercedes manual just says it can be towed 4 down and tells you the process for getting it to stay in neutral since its a bit different.
I spoke to a tech at the dealership and he said he didn't think so but he also didn't know about it saying you could do it in the manual.