I use a docking station and a laptop that is always in the car unless I am traveling, and then it clips out and comes with me.
There are four issues I can identify that will need your consideration:
1) Power supply and turning the laptop on
2) Getting 800x480 video to work
3) Sound card
4) Mounting
1) A good power supply is critical to reduce noise introduced to the system, as well as let the computer and accessories work correctly. I use a Kensington 120w auto power supply wired to a power distribution block in the trunk. Other and probably better options are to use the Carnetix 2140 or 1900, either of which provides power for the laptop directly, as well as an additional 5v or 12v lead which will allow you to power your USB hub and soundcard.
Regardless of the power source, you will have to solder a lead to the power button on either your laptop or dock (will not work with a generic USB dock) to turn the computer's power on. If you have a dock, you will not have to risk drilling and soldering your (more expensive) laptop. I soldered a lead to the power switch on the dock (do a search for this topic) and connected it to a female jack that fit into the hole I drilled in the side of the dock.
A momentary switch in my dash is wired to the male jack that fits into the socket I affixed to the side of the dock. This allows me to power my lappie on from the dash, as well as hold the power button down for 5 seconds to hard shut it down when it crashes. I have it set to hibernate when the button is pushed for less than 5 seconds.
2) If you have a 800x480 screen, you may have problems getting your laptop's video out to drive that resolution. I am running 800x600 and cannot really notice, though I guess it is less sharp than it could be. A program called "
Powerstrip" may help, but not for my video driver
3) Most laptops have poor sound quality, not to mention audible interference due to poorly shield internal components. An external USB sound card is a necessity if you want to have quality sound. This is a topic unto itself and your choices run the gamut from a cheap no-name brand USB dongle, to a decent Audigy 2 NX, to USB DACs that provide get sound (at a price).
4) You will need to secure your setup somewhere. Since I use my laptop for other purposes, I needed a secure, but easily removable setup. I mounted my dock into a plastic case (pistol case from k-mart: $9.99), drilled holes for all the wiring, and cut insulation foam to allow the laptop to fit snuggly, yet be removed. It may take up extra room, but the computer is safe and doesn't risk flying around.
One day I'll post photos, as I think my install is looking pretty clean, with no stray wires and a pretty good sounding setup. Oh yeah, I can play music, watch DVDs, connect to the internet, run GPS software, and play games while doing 80 mpg
Good luck