I have heard that the speakers can be crappy on the Nuvi. That is why I went with the streetpilot c530

I'm pretty sure the Nuvi 360 and 660 can hook up to the TCH's sound system. After all, they offer the same Bluetooth phone feature that the TCH comes with.

They can not transmit their sound through the bluetooth, they can only make and recieve calls through it. If the Nuvi has a Aux output, it can be run that way. I think some more $$$$ might.

I looked carfully at the Nuvi and the Streetpilot. I like the fact that the Nuvi is real flat and good looking, but when you listen to them side by side the streepilot wins the match. The speakers on the Nuvi are on the back so they have to reflect off the windsheild. The speakers on the streetpilot are on the side and fire right at you.

I have heard that the TomToms have issues with the mounts staying on the windsheilds.

Re points below:

Dead reckoning, nice, but I have not found it necessary on 99% of drives. You are always going to get a little more oomph in a mounted system, but I actually value the portability more now that I have it. Example, when my windshield was rocked, I had to drop the car off for the day, so I tossed the Garmin in the rental to do my rounds.

Sound - I have no problem hearing the Garmin with the radio on. I do find the female voice a little clearer.