I had a 1965 Mustang convertible just like this, in green.
I lived in Mass. and never put the top up year around unless it was raining, or I was stationary in heavy snow falling.
Loved that car - kids stole it and took it to Hartford twice....because i never locked it. They'd just cut the top.
They stopped after I saved a local family from a house fire. (not a hero - I just beat on their door and woke them all up)
Stig