回複：真空吸力底座不安在玻璃上，而是安在擋風玻璃下那塊大板上會好許多。先安配套墊。

The best ones are:

http://www.amazon.com/Garmin-Portable-Friction-Mount-Frustration/dp/B002OL2MU4/ref=sr_1_1?ie=UTF8&qid=1365196846&sr=8-1&keywords=gps+mount+dashboard

or this one for TomTom:

http://www.amazon.com/Portable-Friction-Dashboard-Magellan-RoadMate/dp/B004DF1E9E/ref=sr_1_1?s=electronics&ie=UTF8&qid=1365196878&sr=1-1&keywords=tomtom+Portable+Friction+Mount