As you can see there is quite a cross section of ideas that all seem to work as intended.
I've got a 1st generation Zumo 660 and it performs very well. It has a removable/replaceable/rechargeable battery and micro sd card which I load up with music or trips.
It's on switched power, the audio comes through the bike speakers and the Honda comms if desired, and it's mounted to the clutch lever clamp/handlebars with the provided RAM mounts.
It also came with a car mount so I simply disconnect as illustrated by DMAGOLDRDR and use it in my car.
Not sure about the newer ZUMO's but this baby came complete with wiring harness's and hardware for every scenario..... in the box.