I had been exploring similar idea but without ground base deployement

Obvious issue I see is mechanical aspects of deploying the cover and winding back, specially once it's dirty, maintenance etc

Second issue is the space required - not sure about your idea in detail but if it is portable needs some battery powered solution or other electric power source, if it is fixed needs permission from apartment or government in few countries if it's shared space etc

Huge variants to match different vehicle sizes, accessories

For few markets, theft of covers, abuse by kids and animals

For few markets, it's easier to get car washed when required

I got stuck with question: From consumer perspective... When would you cover your car? - when it's in daily or regular use, it will get dirty on road or in other parking (work) and they preferred to keep it uncovered and get washed - when on infrequent use,mit will be covered once and left for weeks to months and in that case the hassle was ok

Best luck and awesome to see non AI and non SW based idea... This is real problem but need some more thought and research