I've e-mailed the support line but have had no useful help, mainly because I don't think English is the person's first language! Double-clicking the downloaded file only installs the driver, so that your computer will recognise your satnav when you connect it (via USB).
The fact that you can angle it only horizontally, rather than vertically, could be an issue. At first I thought it would be necessary to install it upside down in my test cars, which both have very steep windscreen angles and deep dashboards.
In this case you update the maps on your sat-nav using Garmin Express which you download from Garmin's website and install on your PC or Mac.
Once downloaded and installed, the update process is relatively straightforward.
But in fact there's a hidden hinge on the suction cup to make installation more flexible.
Either way, I found I had to place the nuvi Cam further up my windscreens than I usually place sat-navs, otherwise the camera would only record excellent-quality footage of my dashboard.