It depends what you prefer . I think E350 is more than enough , E550 is for sheer performance . It is gonna set you back no less than $ 52K but alternatively you can try pre owned certified vehicles .
I prefer W212 over W221 because I like the way E Class looks for both interior and exterior .
However, I must say W221 is the best looking S Class ever made

 

the w221 looks like a maybeach lol thats why i like it so much. and yeah your right, but when you see the line up there will be a boat load of missing features.

however do you have any input on the transmission fluid lol? I dont want to dump in that non approved one.

 

Any input on the transmission fluid , I would say Dextron VI . It is compatible with earlier Dextron Series too .

 

Does anybody know how to remove the old front seat belts to install the new modules? Do i have to remove the whole seats to do this?

 

 

Heres the dash most of the messages are gone.

Ill have all the codes and error messages gone in a few days.

 

 

if you mean a new seatbelt reel or whatever all you have to do is remove the interior trim from the "b pillar" open the front and rear door, gently pull the seal that is touching the b pillar - then there are 2 "fir tree" fasteners at the bottom and you have to pull on it more than you would think and it comes off. then you are in to the seat belt which if I recall you can just unbolt the reel and bolt in your new one.

the other part of the seatbelt not in the reel secures to the car with a bolt