It makes a huge difference whether that snow fell onto an already cold (well below freezing) car or whether the initial snow was first melting and subsequently freezing to put the car into an ice cocoon.
Hands up everybody who has ever cleared snow of a car only to discover part way through that it wasn't their own car they were clearing ? (Been there, done that). Of course that also worked once in my favor when I found my car more then halfway dug out of the snow in the morning -- Got some spare cpu cycles ? Join Team Helix or Team Starfire!