Has anybody put seats from an older s-class for example a 2004 s430 into a 2011 e class. The seats in the e-class are uncomfortable and looking to upgrade

 

I doubt S class seats would fit as the S class cabin is larger. and each generation tends to have its own seat 'foot print'. and each generation tends to have its own seat control wiring and signalling so the power seats probably won't work..

 

Alternatively , you can have an upholsterer soften your seats . Seat bottoms and thigh areas are hard generally . A good shop can be able to soften those sections

 

I find the seats in our 2016 e350 wagon to be quite comfortable when properly adjusted, and they are the mbtex versions in a 'luxury' package wagon.