Any ideas how to improve hard seats?

[foama]

Hi Folks, any ideas on how to improve (soften) the rock hard driver seat?
I do lots of long distance driving and have just done a few hours driving, and my rear end (butt, arse) hurts as if someone kicked it!
It usually takes about two days until I can sit on anything for any prolonged time without pain after a long drive. I know there is not much meat to my butt, and probably thats part of the problem, but I really can't continue like this. If I can't improve the seat I shall have to get rid of this car.
My daughter's tiny 1998 FIAT Seicento has perfect seats, so much more comfortable, but unfortunately they are totally different and wont fit into this car.

Thankful for any suggestions!