Verified answer

the roof would seperate from the sides. The gutters is the pinch point between 2 different pieces of metal. In otherwords you would have an unfixable piece of junk. Try it at the wreckers on a vehicle that is in much worse condition(T boned) if you don't believe me.

You'd have less wind noise, but you'd get a lap full of water everytime you opened the window when it's raining.