Well... As a guy with too many cars in his driveway "until I build that new 4-car, double high garage," your post got me curious. Check out this site, perhaps:
https://www.extraspace.com/
You may be able to find outdoor parking spaces (think RV parking) and then you could get a decent cover (all of my cars in the driveway have covers).
Alternatively, some storage facilities have units large enough for some cars (8x18, 9x18), but of course indoor storage is generally more than outdoor.
If something more interesting comes to mind, I'll pass it along.
GL HTH