Realistic Opinions of ML 3rd Row Seats???
 

We currently have a minivan and are considering an R-class in a couple years when the minivan is used up. But an ML with third row seat might be an option, depending.

Honestly, how practical is the third-row seat? Can 2 adults fit back there for any length of time? With the third row seat installed, is there any cargo room left? Can the seats be removed easily? Also, this might sound crude, but can a sheet of 4 x 8 drywall or plywood fit in the ML?

I don't believe the current generation ML's are even offered with the 3rd row seat.

My neighbor, who is a technician at the local Mercedes dealer (Penske Mercedes), tells me to stay away from the 1st generation ML, even the last year.

I'd go with the R class personally. Or ask John Doe. His wife drives one.

If you've got young kids they are OK
 

We have a 2002 ML320 with 3rd row. For intermittent use it's a viable alternative. I wouldn;t reccomend it for every day use by seven people.
The seats are relatively easy to remove and store. I'm 6' 0" and 200#.
I would say that the 3rd row seats are for kids under 12, there isn't much leg room (the 2nd row slides forward about 3" - so you los 2nd row leg room too). and for very young kids using anything than a small booster is not really practical.
The 2nd row has a tumble seat arrangement for entering to the 3rd row.
And of course with the 3rd row in place there is little or no trunk space.
We actually use only one of the 3rd row seats most of the time, we just keep it folded flat on the floor or folded into the rear wall, it's available when needed.
I don't think you'd get a full sheet of plywood in there, although I did once pick up a twin size mattress and box spring from Sam's Club using the ML320

I don't have 3rd row experience but I do have hauling experience. For a full 4x8 sheet to fit the rear door would need to remain open. One option is to use the roof rack basic carrier, a 250-300$ accessory. With the carrier on, 3 - 1x4's eight feet long will support 4x8 sheets well up to 200# and tied down well. Option two is a trailer.

Jim