Thanks for that good advice, but both are pretty clean at the moment, and I'm certainly not going to wash them in 30 deg C !!

I'll get back when I've had a go. Do you think there is any point in using my orbital polisher for the dry run?
As long as you can keep the surface wet you’ll have no issues in hot temperatures
I personally wouldn’t use an orbital polisher on the dry run as it’s just not necessary
Once you start using the product you will understand how it works; wet the surface by spraying on the product in one section at a time then use your ‘wet’ cloth to remove it and clean the surface followed by a ‘dry’ cloth to polish off the remainder of the product
I spray it on the first half of the roof to start then move to the windows and doors on that side, then the doors and sill on that side. Once I have done one side I start again with the roof on the other side etc etc then I move to the rear and front
I use it on all the glass apart from the windscreen
The knack is keeping the surface wet with the product while you use your wet cloth to remove it. You only need a quick polish up with your dry cloth afterwards
Every time you use the product it gets easier as there is already some polish left behind