I couldn't find a thread on this and actually don't know where to post it but here goes.
My conundrum: I am used to the "90's" style seating where you'd tilt back the back of the seat and lower the seat itself. I found that in a bimmer (and many high performance cars) the seat has a lot to do with how you experience the car.
Let me repeat/clarify this: The seat position will change the way you experience your car.
I am still looking into finding the best possible position, I am not an expert and really looking for people's different experiences to try to find an optimal "guide". BMW is well known for having superior seat designs and I am really glad (even though I didn't know it at the time) that I got the sport seats, when I get a 328- loaner without the sport seats I can really feel the difference! So I've been trying for months now to slightly adjust the seat to find the best possible driving experience "seat wise".
I have the heated sport seats with memory, adjustable wings and lumbar support. So far I am slowly moving the seat every week more and more upright back, lower seat (with raised knees) and closer (or farther) to the pedals upto a point where my legs are now only slightly bent when one foot is on the brakes and the other is on the foot rest (automatic tranny). I am slowly finding this position gives me more control of the car in any circumstance and also how you experience bumps/road imperfections is entirely different this way that when your back is tilted back even slightly. This way seems like the "disturbance" is minimal - almost like upgrading your shocks with faster responding ones (not really but you get the idea).
One area where I am clueless is the lumbar support - I have the circular 8 way dial. I would really like to know how this thing really works, I am not sure the which way to press it for what exactly, and I couldn't find anything useful on this online. When I played around with it while the back of the seat was tilted back I always ended up so uncomfortable (even to the point that I got back aches) that I always went back to eliminating the bump in the seat back as much as I possibly could. Now with the back of the seat upright, apparently this thing has a purpose that I may be able to use. It feels that there is a spot in the lower back that you can set it to to help your bake brace against when you push the brakes hard or accelerate quickly. But it's kind of a hit or miss still on where it should be - any input here much appreciated.
As for wing adjustment, I started wide just barely noticeable and kept tightening until it was too tight to the point it was uncomfortable then dialed it back to where I got the seat to help hold me upright in turns without any play in my back while also not very noticeable in straights. I am not entirely done but have no complaints on this (And I feel sorry for those who don't have this function - especially if you do any suspension modding as these wings are all about how you feel during turns.
I found this a while ago and took it as a starting point:
Sorry about the lengthy post, let's hear your thoughts, if this is in the wrong section, please let me know where to post it.