not hard.lck of support for the area round the small of the back.i went out and bought a blow up adjustable lumber support from halfords.mucked about untill got right setting.feels great now,no problems.
yep got exactly the same thing when i had mine i got a "backfriend" , actually bought it for my SPAM but found it invaluable if going long distances in the soul as found a lack of lumbar support made my arse numb!it got painful after an hour or longer ,reckon any lumbar support cushion will sort this out .
im in a job where we have to drive all day luckily for me the seats we have are pretty good they have two inflatable back sections one for your lumbar area and another for the thoracic area (thats the bit above the lower back)!but they are adjustable and thats the secret really if you want to avoid low back pain in a car you need to be able to alter your seat and back muscles will protest quite readily if you sit in one position for too long!so if you want a real good back support one with an inflatable support really will be worth it especially if you already have a tricky back!i know they arent cheap but you will only buy one so make the money work for you its cheaper than a new seat ! rocaro even use the pump type back lumber supprt intheir seats now! the backfreind i bought last year was about 50 quid ! a lot yes but it made my SPAM seat useable and stopped the soul giving me a numb bum!