Is there anyway to configure the rear seat for 3 adults? I like the trimmer dimensions of the 4 door CLS and I don't need the extra dimensions of the S550 but the back seat is a deal breaker for me. Is there anyway to configure the back seat to be a "regular" back seat with seating for 3? Sometimes in social settings I need to be able to take extra people in the car...

lol with right amount of money anything is possible. I remember someone on this forum or some forum doing a swap..and putting in E class rear seats in(i might be off tho). But that's very costly..

Your best bet in that situation is to put the thinnest chick on the console. It will support the weight, just don't ask me how I know.

I have done that too. I can say it will support up to 125 lbs for sure.