The geometry has some problems, there are some coplaner faces and some small irregularities, How good do you need it? Try this, open the seat top for editing, select all and set soften smooth to 180 and check soften normals and soften coplanar. Then apply your texture to the softened surface. Good enough?
You could also use the texture as “projected” but the round edges will look odd as the projected texture will not wrap around but elongate as the projected surface curves away. Options.
