So what are people using & recommending ? Want to cocoon the E39 for a few months so need a good quality cover that doesn't cost the earth.

This tailored StormForce Plus looks good (especially with the 360 hemline tension string) - it's pricey enough, but I suppose that's the price you need to pay for tailored for each model, breathability, fleece lined and won't blow into the neighbours garden with the first bit of wind....