Another solution :)
you have also the free catalog of the Free Pcon planner ;)
https://portal.pcon-catalog.com/fr/category/seat/ (98) !

No need to donwload pconPlanner!
Models are free direct access!
Maybe you pass more time to find a model that you want than modelize it! :)

Hi all,

A possibility for a such process with a flow method.

First I made a profile (blue one) to have a surface.
Duplicate this blue surface (and move it) to have a second.
Blend the edges to have the round part and join them to have a solid.
Array this solid to have a set of solids.
The first one and last could be customized (cutting half and BlendCap) to have the two wider sides.


Red surfaces to flow give the round form on top.

Next, the green curves to flow to have a nice result.

I think it's possible to flow in only one operation but step by step is more easy (for me) to understand the process.

And the advantage of this last Flow method is the possibility to move the Control Points for search any form! ;)

Thank you guys

I followed your advice and used soft loft for the front and curve Network for the back.

in the end I used the joining part to make the seam.

A special thanks as always to Michael who is always very patient and helpful.

Great result you have made a perfect model, congratulations.