For your first question, there are plenty of mounts for dashboards/cup holders and a few other places if you dont want to install it into your dash that shouldnt be a problem. $250 on the monitor is no problem either, I get a lot of my stuff off ebay because its a lot cheaper but for $250 you can get a really nice new touch screen from just about any place. (I would still suggest ebay) http://cgi.ebay.com/New-Lilliput-7-T...ayphotohosting
Thats not bad, comes with the dash mount and every thing.
As for software media engine is pretty cool, seems a little buggy still but other wise well worth the money, here is a link to an Audi skin for that software, browse the sit for the actual software you might want to test it out on your PC first and see how you like it, but it has GPS support and what not.
but most software will work on Windows XP with no problem that also shouldnt be a problem.
In the power settings of a laptop: Right Click on desktop > Properties > Screen Saver > Power there is an option in there some place, cant remember the exact location but you can tell it to "do nothing when I close the lid" so you can keep it on all the time without having to use a docking station. As far as working the power on/off button goes You will have to do that manually unless you want to take apart your laptop and solder in a button. You can turn it off through Windows but you will always have to open up the laptop turn it on then close it. Seems to me like the hardest part will be trying to find a place to set the laptop where its out of the way but still accessible to turn it on with out it being in the way.
not that EXact brand but I was just using that as an example.
Wow, I just realized how long that post was, sorry.