I re-cleaned my soft top on the weekend, trying the 'Turtle Wax' kit that comes with cleaner / conditioner.. I normally use the Autoglym kit..
However, after applying the conditioner, it rained unexpectedly, so I waited for it to dry and reapplied it to the front part of the roof, and I wanted to use it liberally so then broke out the remaining Auto Glym to finish the rest of the roof..
It was interesting to then see how it performed after a day of pretty terrible rain..
The turtle wax really doesn't repel water anywhere as proficiently as the Autoglym.. In fact you can see the transition from Auto Glym to Turtle wax quite clearly.
Of course, modern Mohair roofs have a rubber layer so don't techically need to be waterproof in the fabric layer, but having it relatively water resistant does help keep it's shape and stops dirt getting more ingrained.
My next test might be G-Teknik and Fabsil..