So, I'd love to upgrade my radio to a NAV version, but I'm not trying to spend $1000 to do it.In the past 3 yrs, I've went through 2 Garmins (a Nuvi an a 1350T). so I tried using my Sprint phone with Navigation. It worked fine for a short period of time. Now the GPS antenna in the EVO 4G is flaking out and will cycle itself, dropping GPS signal when you need it most. So that's worthless, not to mention, a 3" screen is hard to see, especially factor in the vibrating around in the rough-riding truck..What do you guys use/do for GPS in the 2gen trucks?