shavedmax
+1y
if prepped properly and sealed up good it shouldnt have cracked. i've seen some really thin plastic crack because it wasnt prepped right and some thick ass plastic not budge. roofs are tough since itll get alot of heat from the sun, but look at how may people cut up hoods to put cowls in. that hood has to be covered from end to end practically in plastic(whether thick or thin), and that gets a beating from the sun and the engine.
look at overhaulin or boyd's show. their cars are covered from end to end in plastic. you're telling me they keep it all less than 1/8". bull. the metal may look straight but once the filler goes on they dont take it off because it seems too low. they just slop more on.