I have heard dozens of 03/04 Cobra owners complain that the stock drivers seat is uncomfortable because it tis too tight on the side of the hips/thighs. I call it the "ass clamp" factor, just plain too tight of a seat to sit in. I owned a convertible Cobra for 2 years and it was uncomfortable but bearable. Just sold the vert and bought a coupe and it was far tighter and awful to sit in. I am not a fat person, size 36 waist, moderate beer drinker build but no reason to be miserable in a normal car seat. Just plain got fed up with it today and decided that it was gonna fit me or end up in the Detroit River.
While taking my drivers seat out I found quite a surprise. About a handful of moldy sunflower seeds, a really nifty pair of tweezers and $3.37 worth of coins under the carpet (near the holes)(just bought this car used, not my seeds or my change.) I guess I will just consider it a rebate.

It is only 4 15mm bolts/nuts and one electric clip to remove the drivers seat. Set it on a large, clean surface and flip it so you can get to the bottom.

Once you remove the base with all the motors. compressors on it and unplug the two electric clips you see these three retainers.

Ease the foam up on the sides and you will see these seat side bolsters. The inflatable bladder is attached to a plastic back and the whole thing is supported by a metal bar. It is welded at both ends. I simply stuck a prybar in the side and bent them out.

After the mod it is a bit more wrinkled but tolerable.