I also have one of these covers (still awaiting my D to be delivered). You get them from a company called Classic Additions
https://www.classicadditions.com/index.php/. You do need to email them though since the online order form does not list DeLorean's. I have mentioned this to them a few months ago and they promised to add!. They are a really friendly company, good to do business with from my experience.
If you want exactly the same as in the photos above you need to specify
Super Soft Stretch Indoor Car Cover - M - Light Grey and specify Logo for Car Cover as "DeLorean".
Regards
Gareth.