The Motorola A925 is a bulky ugly phone... but I bought one when they sold it for €65. Not a phone to carry around, but it has a built in GPS and would do great as a GPS in the car. The reception is to bad though, so I bought an external gps-antenna on Tradera.com. To make it fit in the car a carholder and a carcharger was bought from Fone-R-Us (http://stores.ebay.co.uk/fone-R-us).
As GPS software the free MapViewGPS is used, you find it at http://www.wild-mobile.com/eng/projects.php.
To make it easier to start the GPS the top menu was altered with AppickerConfig, http://my-symbian.co