Window tinting may obstruct GPS signals!

How many of you who have nav and are think of having or have had your windows tinted saw this little gem in the Navigation System Owner's Manual, page 306?

NOTICE
The installation of window tinting may obstruct the GPS signals. Most window tinting contains some metallic content that will interfere with GPS signal reception of the antenna in the instrument panel. We advise against the use of window tinting on vehicles equipped with navigation systems.

I don't have the Nav but I have issues with Metalic Window Tints with AM/FM and Cellphones in most BMW(s) I have worked on. There are ceramic tints and charcoal based tints that don't have these problems but they definitely cost a whole lot more than the usual $100 to $200 shops. I tint my cars myself and always use charcoal based tints to avoid the signal issues.

I have charcol based 35 on all my windows except the windshield of course
and no problems at all.

I have 3M film on my car and GPS works fine.

Do you think it's a case of Toyota covering themselves, just in case?

You'd think that if this had really been a problem, the warning would be placed somewhere a little more prominent than the appendix of the nav system owner's manual.

I guess my tint doesn't have whatever it is that interferes with the signal because every last window in the car has tint on it. Only the sun strip on the windshield was the cause a problem for the LKA and I just cut a nice looking notch out of it to give the camera a clear view. Because of the angle of the windshield and the fact it has the black strips near the rear view mirror it blends in really nice. You can't hardly even notice the notch of clear glass there except when the sun hits you just right. I can deal with that. I guess just ask before getting your windows done to make sure there isn't anything like that in it.