I use Ragg Top ..
They offer a two can kit which includes cleaner followed by a conditioner / waterproof spray.
You can read up on their claims if you are curious, and yes I do understand that the cloth cover does not need to be waterproof, but I do appreciate the water beading up and running off the cloth top.
When I was detailing the Zed (AKA for hanging out in the garage)
I cleaned and siliconed the docking mechanisms as there is a roller that has the potential of sticking,
Next I lubed any other 'docking' areas with electrical silicon grease (just to keep those ares flexible ..
Lastly I used white lithium grease on any of the roof mechanical joints ..
ie Raise the roof and carefully spray, making sure to wipe of any excess.
The roof slowly retracts so this might take several attempts to complete.
Make sure you dust any exposed crevices..
The top looks great and the mechanism runs like a hot knife through butter...
Bumpy
ps ..Top looks like the one above ... I do it twice a year