I am on my second CA cover. The first lasted about 4 years, the current one has nearly had it also after about 18 months. The inside is breaking down, leaves a fine powder over the car every time I use it, and no longer keeps the rain off totally like it should.
I emailed CA to ask what they thought a reasonable length of time one of their covers should last. Got no reply. I used to recommend these covers, not any more and I wouldn't buy another one off them.
Might try one from
www.airflow-uk.com next. Spoke to the guy, says they are thicker and better quality than a CA one. Triple layer with a soft inner layer. He said he has had one on a car for 4 years, its very dirty but still doing its job the way it should. Pricey for a cover but I have no garage so limited options.