Covercraft NOAH CTS-V car cover from webcovers.com (or any internet vendor of your choice. Made a little longer than the regular CTS cover due to the airdam.
I have a NOAH for each of my vehicles. I occassionally use em as dust covers/scratch protectors for the cars in the garage, too. But only put a car cover on a spotlessly clean vehicle, otherwise it is just a scratch generator.
If you stop by your favorite Cadillac dealer they have a nice accessory catalog with various V pieces including car covers. When I tried to buy a V logo'd cover I was informed that the GM supplier had gone out of business. It turns out there are no V logo covers left in dealer stock according to the search my local dealer did. However, when they searched on the CTS cover with the Cadillac wreath, they found a few still in stock. I bought mine from a dealer in Dallas. I think there was also one at a dealer in Atlanta and another in Ohio.
I really like the cover. It's black breathable woven material and fits like a glove except for one thing. They failed to accomodate the roof mounted XM antenna. I came up with a slick solution, though. The bag that comes with the cover is made of the very same material as the cover. So I took it to a local awning company and they sewed a little antenna boot into the cover, using the bag as a donor for the material needed. Perfect fit.
I have a Covercraft as well and the fit is great. I have the Superweave for the Cobra and really like it for outdoor occasions, so I tried the Superweave, which is a little thicker and more weather resistant. While it is very slippery, it is hard to put on and off with a breeze blowing, which we get frequently in summer. So I ended up getting a Dustop to go under it, because it is rather heavy and very plush.
It turns out to be a great solution (not cheap though), which has the combo of the best outer layer and the best inner layer, similar to a Porsche branded 2-ply car cover that one of the guys here at work uses. It doesn't get tossed around by the wind, so I don't have to worry about scratches now either. I don't fear bird poop or tree sap either.
Check out the CAR Motorsports Custom Embroidered CTS-V Car Cover. Same German Madeira Thread Embroidery that is on our Custom Floor Mats. You get embroidery on the storage bag, front of car cover and on the rear of car cover. It is extra long, covers the wheels, comes complete with cable and lock as well as a pattented strap tie down system. Reflective coated silver finish and slick inside surface. You get easily get the cover onto the car and back again into the storage bag. Warranty is a limited lifetime. All this for $199.95. Link below. 1-877-367-2279 toll free.
A friend bestowed a Griot's custom car cover to me as a gift. I immediately threw my old "breatheable" cover in the trash. This is advertised as the finest cover around, and I must say, it is one FINE car cover indeed. It may even qualify as the Mother of all Covers! They have different models, depending on whether you keep your vehicle covered in the garage for storage or outside. Mine (the indoor type) has a flannel lining that minimizes scratches when it's installed or removed. Highly recommended. Their website is: http://www.griotsgarage.com
Each cover is custom-built with as many options as you can afford.