Personally I do not use soap on any part of my cars (cuts wax, etc)....but that's just me.

And.....only thing the cab roof gets is water, lint rollers, and Ragtop.

 

I use the Raggtop kit as well. Seems to be excellent. Make sure you let the top dry thoroughly after cleaning (part 1), and then, as noted, cover the bodywork before you apply the spray.
I do use car wash soap (very mild/bio-degradable) on the top with a light sponging. The protectant seems to hold up for quite some time.

 

Application interval is dependent upon where you live. Since you don't mention that it's hard to tell you. Harsher climates require applications several times a year, while benign climates would call for it perhaps once or twice. Raggtop or 3M's Scotchguard work well, but mask off the rest of the body and glass when you apply it.

 

raggtopp for cloth

works great.

 

All Porsche convertible tops are made from what's referred to as German Cloth. You want to get the RaggTop cleaner and sealer for "cloth" tops.

 

What would you consider harsh? Exposure to a lot of moisture and/or snow?

My car is never parked in the open sun more than a few minutes, and is always garaged or being driven somewhere. It's seen very few instances of rain, and it was brief. Only factor for me is the heat. What would you recommend?

What signs of wear do you look for if you're not doing it enough?

 

Thanks for your reply GreggT