I have an older Nuvi 765 which I think you can still find on Amazon. It has stereo Bluetooth but the best feature is that it has a headphone jack which I use to connect it to a J&M system through a Mix-it2 which also connects audio from my radar and phone. I've used it in some heavy rain without issue and it costs a lot less then a Zumo. You can not make calls with it though using the Bluetooth connection. You have to be connected by Bluetooth to the phone for that.
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