installation of convert top 63 dart

Hi there , i'm not sure if my top has been fitted correctly as top has torn on both driver and passenger sides just behind where the rear passenger window is on the body. its very tight. where my top has been fitted around the rear end and side it is on top of the body with the chrome surround screwed down on top. i hope i'm making sense.I've been advised that maybe the top should be underneath the body so the water runs down into the water drip channel around the boot well. any helpfull suggestions would be appreciated.Jim