Amazon has the Garmin Portable Friction Dashboard Mount for nüvi Series and StreetPilot C5XX Series GPS Navigator for $15. Shipping is $6 or free with prime or on orders of $25 or more.
Technical Details
* Vehicle Dash Mount For Use On Any Stable Surface
* Securely Holds Nuvi In Vehicle
* Does Not Slide Or Detach While Vehicle Is In Motion
* Adjustable To Position Nuvi In Variety Of Angles
Amazon.com: Garmin Portable Friction Dashboard Mount for nüvi Series and StreetPilot C5XX Series GPS Navigators (C530, C550, and C580): Electronics
Garmin Portable Friction Dashboard Mount $15 (FSSS Eligible) 
