If you value your paint, refrain from using a vehicle cover. You are only inviting scratches. Only washing should ever come into contact with your paint.
I do not even dry my autos with a towel. I use a blow dryer.
A superior option is a Car Capsule. Their cost is around $2000, although they are well justified by the security they provide. It resembles a protective enclosure for your vehicle. Prevents the ingress of dust, rodents, dampness, filth, pollen, and similar contaminants. I maintain one in my garage, allowing me to park my R8 there whenever I intend to leave it unused for an extended period. It is equipped with a HEPA filter that purifies the air prior to its introduction into the bubble.
I use a Showcase, which is appropriate for indoor parking. They also produce outdoor variants.