a lot of questions can probably be found at this link, if only the link was easier to find...:
for a easy to install/remove solution, i would recommend going with a small netbook.
the install location can be anywhere it fits-- the most common places is the glovebox, center console, under a seat, or in the back cargo area in a unused cubby.
most of the hardware you pick is personal preferance-- if a netbook wouldn't work for you, than you could use a bundle from the mp3car store, or build your own.
1. case: i don't use a case, so i can't recommend any(i hear mo-co-so cases are nice).
2. mobo: i like my zotac 9300...
3. processor: my pentium dual core is nice, but overkill for most installs. and board with a integrated processor would be fine
4. ram: it is typically recommended to use about a gig, but i use 2..
5. dvd: i like usb dvd drives-- they are easy to install/remove...
6. hdd: i only recommend seagate 2.5" drives, but anything with enough capacity will work(if you have some spare 3.5" that would work fine)
7. monitor: if you have a double din slot, i would recommend the bolt in double din monitor from the mp3car store:http://store.mp3car.com/ProductDetai...ctCode=MON-067
8. kb/mouse: i keep a wireless keyboard/touchpad in the back seat for this:http://www.tigerdirect.com/applicati...8753&CatId=537
9. power supply-- this depends on what route you would go: a netbook/laptop would probably use a carnetix 19volt power supply, and a normal pc would probably use a m1/2/3/4, or dsatx power supply..
10. there are some usb monitors on the market, though, they don't do to well with video, so you might just end up using a vga splitter, and 2 more vga monitors..