GregS, You posted about them before and I checked it out... I plan on doing the p-flow condensor for sure..I have never heard of that Diesel-kiki compressor... seems like everything I start to fix I wind up having to learn everything about it in order to do it right... seems like there are no generalists left in most fields that you can ask for an overview and get both the theory and up to date specifics combined in an answer....

On the seats... I have an 'excessively springy,non supporting ' seat in my 80 240d and just the opposite in my ex 300td 81 ... you might be able to take it apart and bend new heavier springs to fit the seat frame... bend them cold of course to maintain their spring...

A good auto upholstery shop might be able to do something for the back part of the seat, as in shapeing it to fit your needs..

I have long planned on taking inner tubes and cutting them where I could put them under the seat with a leather (naturally) cover over them, to protect them from sharp stuff and keep them from rubbing a hole where they contact stuff.... I could adjust them with air pressure that way...

I am the proud owner of a manual shift, manual windows,manual ac control,non sun roof, 240d. Simple is better for some things.