Joebill, I have Clearviews on my Everest, and while they have been there since purchase (supplied and fitted by Ford), I had to remove and replace them once to replace the connecting electrical adapter cables with upgrades provided by CV (initial issue with mirror indicators not working when rear window demister was on - fixed with new cables). I reckon my fitting was a better job than what Ford did, and yes, there was a small gap (~2mm) on the leading edge of the mount. After I refitted the mirrors, I filled that gap with black silastic (the mirrors are black), and all looks good. A 5mm gap seems a bit much to me... can you tighten the mounting screws? The mirrors have been on the Ford now for 3 and a half years, and have travelled ~38k km (the vehicle is not our daily drive). We also had CV mirrors on our previous vehicle, a Prado 120, for 9 years, and they were a good fit from the start.
Cheers
Greg
Perth WA