Hi Speedy Lidles have some car seat covers for less than 20e for the Captiva, won't help the fraying but might stop it getting worse.Washing my car for my trip to Italy and the UK yesterday and I broke the nozzle for the rear washer took it to the dealer where you had yours and he sold me a new one and fitted it for less than 15e.
Off Friday on round trip to Italy, Croatia and on and up to the UK and back again, that will give my car a good testing, oh yes and towing a caravan.
Good luck with the seats