I got a carolina carport last year and it is wonderful.

Mine has open sides.

I ran a rope from one end pole to the other..... up about 6 foot high and use a tarp as a curtain when rain is in the forecast.

All I did was doubled the tarp over the rope.......simple fix for blowing rain and when sun comes out I push it to one end.

Make sure it touches the ground and do not connect it at the ground so it can swing up under the boat trailer when the wind blows strong.

This allows for the rain to just run off at an angle.......under the trailer.

I attached the rope and tarp to the inside of carport so it will not have too much wind resistance.

You might want to attach one or two bungee cords half way to help support the tarp.

Robbie