HI Richard.
One word of advice......there are car covers and there are car covers......and you do tend to get what you pay for.
I run a classic and sports car storage business, and I have tried a fair range of covers from the cheap to the ridiculously expensive! The ones I now offer as standard for customers car are supertex covers supplied from Italy. They cost around £70, but are the best I have found for protecting the car and have a very soft liner. I have these on Ferarris, Bentleys and a host of other very expensive cars and they have always done the job perfectly. Some cheaper ones I have bought in the past have had the linings de-laminte over time, and have become a bit abrasive on the paint, or seem to build up static and attract all sorts of dust and crap.
Hope this helps......just my experience...........