Just purchased my second XLR a couple weeks ago, traded my 05 for a new 09, and read in the owners manual Not to apply glass tinting to the vehicle windows as this will interfere with the GPS signals. When I bought my 05, it had aftermarket tinting applied to the side windows and seemed to work fine. Anyone have any advise? In Florida it can really cut down on the heat and I would like to install to the side windows if I can. Thanks.