I just did this to my '89 cubby... 
 
Instead of straps to the top of the windshield I used adjustable poles to the deck outside of the windshield (and about even with the compass or so). When trailering, or in weather when I won't use it, it folds in the boot in front of and at the base of the windshield. In the summer when I will be using it throughout the day its stays folded in the boot but over the windshield and above my head. 
 
I bought a Carver model number 4A5487UB (96"L x 85"-90"W x 54"H, Linen colored Sunbrella fabric) from Boat Covers Direct. The poles were Carver #62014
		 
		
		
		
		
		
		
		
		
	
	 |