I have been looking at other car makers convt tops, i.e. Mercedes, Nissan, BMW and they have a rain gutter sewn into the edge of the convertible top, around the windows. I think with a curved sewing needle, this would be pretty easy if you could find the right stiffness of material. No matter what adjustments I make on my ragtops, I get leaks in heavy rain.
On my 89 I find the water drains off the windshield, runs about 1 below the top of the door windows and drains down the non-existant B-piller. I have also thought about coming up with some kind of deflector to go between the A-pillar and the weather stripping to change this flow. I'm talking a very thin black piece of plastic to change the airflow/waterflow. Any thoughts on this?

 

Yes I know what you mean, the tops scertainly aren't as well thought out as some of the euro cars like Volkswagon for example. The rain gutter thing is a great idea! I'll have to take a look at mine and see what comes to mind.

 

I don't know, I still have the original top on my '91 Z28 (from what the prev. owner says anyway) and I can't find a single leak, not even when I spray it with a hose set to the highest pressure I can get out of it. Maybe I'm just not looking hard enough?

 

My original top '89 doesn't leak when I wash it, and I don't drive it in the rain.

 

Well mine leaks. As a matter of fact sitting in the drivers seat I can see daylight over the window of the passenger side. Needless to say my car needs lots of work.

 

Mine leaks on sunny days.. lol

 

My 89 Top frame and weatherstripping (minus the rear top to tonneau cover seal) has about 210,000 miles on it. So that could be a lot of the problem. However, my 92 Z28 with 43,000 leaks, mostly at highway speed in heavy rain. Comes in around the A-pillar to window weatherstrip meeting area. I also get a dribble down the windows once in awhile while just washing the car.

On the 89 I can see lots of daylight, especially the bottom part of the window, where it meets the top B-pillar.

I just think a small, almost unnoticable, tasteful rain driprail type deal on the A-pillar would go a long way to deflecting water away from the convt top weak points.