How can I mount my GPS on the dash?

I just bought a 2003 325i and am trying to mount a GPS on my dashboard. I tried the dash mounting sticky disk that came with the GPS and even had them send me a new one because I thought that maybe the glue had dried out. But neither the new disk, nor velcro or double-sided tape will stick to that dash. Has anyone had this problem? The suction cup works fine on the windshield but it kind of obstructs the view. Help please. Oh, and yes, I did clean the dashboard before I tried to stick the suction cup disk.