Outdoor Car Cover

Hi everyone,I just want to ask fellow Type R Owners if anyone has or has had a car cover and are they any good. I've read that you have to be really carefull that your car is fully clean before you put it on to avoid scratches.Also read that the ones with built in ventilation are good. I've also read that some covers have a few layers with the inner layer being soft so as not to scratch. The reason I'm asking is that currently the cars are parked under a cantilever canopy which is super. As the garage was too small and the canopy is ideal for protecting the car from bird droppings.However we are moving house and can't take the canopy with us .I just want to cover the car while we're away on holidays. Any information or advice would be greatly appreciated.
Regards Fred.