I'm having a little trouble reinstalling a 190 e back seat. Any advice?
 

My car is a 1993 190e. I had to take the rear seat out for a few days and now I'm having a devil of a time getting it all the way back in where it locks in place.

Bottom of Rear Seat?
 

I know you've tried this...

Start with the Seat Bottom angled at a 45 degree angle (with the front up-most)
[You are trying to "Scoop" the Bottom under the lower portion of the backrest]
As you are lowering the front of the Seat Bottom...continue pushing the front
of the Bottom rearwards and finally press the front of the bottom down to hear the latches "Click" closed.

That does sound similar to what I have tried and I have been close but no cigar. I will try again though based on your advice. Thanks a bunch for your reply. :)

UPDATE: Thanks to your reply I tried again. I still was having a bit of problems so I took the seat out and noticed a 3rd seatbelt was back there possibly hampering the reinstall. I pulled the belt out and then followed your advice again and boom it snapped right in. YAY! :)