Gidday JL
I don't know if you get the same seats we do here in Oz, but after a day driving in mine, my back doesn't hurt ... I'm 65+, with a chronic bad back since I was about 13 y.o.
A friend and I went for 300+ kms drive the other day in my 2006 Fox. He is nearly 5 years older than I am, and currently has serious back pain, arising from serious disc problems and arthritis in his spine. After a day driving and frequent stops to take photos, with him spending the day as a passenger, he was fine.
When my own back is giving me curry, I find that driving in either my ex- 1993 Impreza or my 2006 Forester is the most comfortable place I can be; even if driving all day. Not as a passenger in the Impreza though. It's the getting in and out of that car that was hard for me, specially on the passenger side - due to the way my back is damaged, no doubt. The Forester has a far better seat "bum height" for me ... :iconwink:
You might just find the seats more comfortable than you think they are.