My favorite choice for my Gen 3/4’s is the factory cover. A lot say every type of cover can scratch the car and technically that’s correct. I only use my covers for over winter. The rest of the time when I’m using them, I just spray them off and detail them.
There is a seller on eBay with brand new Mamba covers and he typically takes reasonable offers on them around $250. With that being said he’s got the last NOS of them that I know of and I bought a couple myself to hang on to for down the road. Hope this helps.