A. A. Best co. User ID best-man
40 years in the convertible business, 39 years hands-on installing
There is much confusion surrounding the rain rail on the Mazda Miata.
Hopefully I can clear up some points.
What is a rain rail?
The Miata rain rail is a plastic trough that is mounted under the rear window. It's purpose is to direct water to the right and left rear wheel well areas, where it can exit the car through drain tubes.
Can I reuse my rain rail?
Often the rain rail is reusable. However we are finding that the older rain rails are becoming brittle with age. While they are still functioning on the car, they are often damaged during removal and reinstallation.
Must I attach the rain rail to my new top?
No. The only reason that was done was for speed of installation at the factory. You might even cause a fitment problem if the rain rail is not installed correctly.
The rain rail will mount with the same studs and nuts that fasten the rear of the top.
Can I install a top without a rain rail?
It can be done, but water will leak into the car.