USB cable connected to Zaurus SL5500, in cradle on dashboard (used for LAN)
I found the Z hard to read on the dashboard of my pickup, but that may be a result of my mediocre vision. My old truck came with a ceiling mount for a CB radio, and I used that to mount a bracket to hold the Z in a more-visible location. Not only was it easier to read, but it was closer to my normal line of sight: not exactly a "heads-up display", but safer than frequently looking down. It was also out of direct sunlight, so I didn't have to worry about UV damage or glare on the screen.
I'm thinking about trying to come up with a sunvisor mount for the new truck. But I might splurge on one of those overhead consoles like they use for custom vans, and mount to that.
I wouldn't trust the cradle to hold the Z without modifications. I used a bracket out of a Case Logic "Strongman" case. If you want to use the cradle (which, granted, is nice for cabling simplicity), I'd strongly suggest finding a way to attach some sort of elastic to hold the Z in place when jolted.
Suggestions wanted for ways to control the MP3 server
You absolutely want something you don't have to look at to operate. If you're going to use a laptop with USB, I suggest getting a cheap gamepad or joystick. There are apps that will convert joystick movements into keystrokes. You might even dismantle the gamepad, and wire up switches in a panel of your own design.
Ran