I have a Garmin NUVI 660 and love it. It has built-in Bluetooth, and the sound quality is quite good. It also has an SD slot. I have a 4GB card in it, so it's like having an IPOD in the car. It uses an unused frequency on the FM band. Setting it up is quite easy. It also has WAAS capability which increases the accuracy of the unit. I paid about $400 last year, so the price should have come down quite a bit. Anyway, my two cents' worth.