Yeah I am aware of this and spoke with the good folks at Valentine who educated me on the best way to test when I first bought the car. So, like others in this thread, I am happy with the V1 G2 performance, if you're not maybe you should switch brands.
My V1 Gen 2 works just fine in that space left of the rear mirror and high on the windshield, front, rear and sides. So I'm not sure what is happening with you situation. BTW I have the thermal/acoustic glass all around.
I use the Valentine 1 Gen2 and I love it. Great range, multi-mode selection for different driving environments and you can hard wire it very easily into the center of the windsheild pod. 1 think to be aware of is to mount it as high as possible on the windshield, into the black perforated strip...
I have owned Porsches since 1980, in several different states. I noticed it immediately and it seems to get worse as time goes on, usually Suburus, Mitsobishis, BMW and usually younger drivers. I typically ignore them - seems like they don't have a lot to lose if something goes wrong.
As a point of clarification, I do not want to repaint my wheels, I want to have touch-up paint for the occasional stone chip - so I need the paint codes that match the wheel colors, not the car color, that I have.