I used a canvas (tent) waterproofing on my top, I think I did 3 coats and gave the rest to Alex, you can buy the stuff at Canadaian tire in the camping section, spray on or brush on. its like rain-x for your top, with enough coating the water wont want to leak inside the car..it will just quickly repel off of it.

other then that I'm no help as my car is stored 99% of the time in my garage.