What's the best cover around for outdoor (under carport) use?
While I have not had to test mine outdoors yet, I am very happy with my Coverking Stormproof cover. Specs and reviews for it on the interweb.
I use a CoverCraft NOAH custom cut one from your favorite on-line site. Autopia is in the link. it runs about $200 if you wait for a sale. I did have one fail after 2 years, and no problems with covercraft honoring the warranty by replacing it.