I don't SORN my Mog - trad.
Two reasons.....
I enjoy driving it.
I need a second car as

uses the tintop.
Buy a cheap runabout to take the Mog off the road?
Only under certain conditions :
Car needed work that took a long time.
Otherwise I would only SORN her if I was unfit to drive for a significant time.
There are plenty of decent weather days to get out in addition to the errand runs and golf days.
Yesterday I gave her a good wash including the underside which is well protected anyway. Perhaps wing liners/mudflaps would help so another consideration...