mine is secured where you would normally put your tax disc, but on the other side of the car. The only way it would obscure my vision is if I was Peter DinklageIts not illegal per se to have a sat nav on the windscreen but if you had an accident then the fact that your vision was potentially obscured may work against you. The MOT covers it under "drivers view of the road" I think.
Re the covers - testers are not allowed to remove things like that to inspect items underneath (battery security etc) so they note them as an advisory (unable to remove to inspect underneath).
it's as much of a obstruction as the tax disc, he's just a jobworthif it within the swept arc of the windscreen wipers then its a no no re the MOT!
"Where items are present in the driver’s view (such as a sat nav, air freshener etc) that would justify a Reason for Rejection, the tester may, at their discretion, remove the items prior to the inspection. This fact should be noted on an Advisory Notice."