Never have had a rag top before but my wife's 2005 mustang GT has a tan canvas convertible top and it is mildewing bad. I keep the car washed and it never really was an issue when we lived in SC but now we're in an apartment in WV and it sits outside and the mildew is very visable and looks awful.  

I need to know what you guys/gals with experience use to remove mildew and then what I should use to treat and protect the top.  The car was inherited by my wife when her grandfather passed and means a great deal to her so I'd like to keep it up as well as possible.

Thanks
Best Regards

Try Meguiars Convertible Top Cleaner.

http://www.autogeek.net/meguiars-convertible-cleaner.html

Will probably give that a shot Meguiars has always put out quality products in my experience.  Has anyone tried this specific product with good results?

What ever you use, DO NOT USE ANYTHING WITH CLOROX/BLEACH IN IT!  I used it on mine and all the stitching rotted out in 6 months time. I never could get mine to come clean and eventually replaced it when the threads fell out.  I spoke with my top guy and he took one look and told me I was parking it under trees.  Yep, trees kill a top quickly. Even if you can't see it, it gets sap on it that molds up.
With my replacement, the first thing I did was use RaggTopp cleaner and protectant.  You might can try the cleaner, but if your mildew is set, I don't think anything will clean it.
My top is 3 years old this month, still looks like the day I installed it since I never parked under trees and I used Ragg Topp on a regular basis.  Unfortunately, all that care was a waste of time.  Had a woman cause a 4 car pileup on the interstate and my '95 totaled in August.  I'm planning on parting out the car here soon and hoping someone needs a complete top.