Stephen
Having had to investigate the hight of my van (awning rail)prior to the purchase of an awning, I found that the only safe way to get accurate info was to measure it myself.
The hight quoted on the web and the paper spec must have been to the highest point, maybe the status arial, or the roof light.
So as I think it depends on what you need the measurement for, you may want to get the tape measure out.
Rob