Holy cow! That's such an awesome idea! Truckers spend so much time on the road, I am surprised I hadn't thought of this until I saw this thread.
Awesome job on the install. LOL @ the dos commands. This install looks slick as hell man. Your brother will now be able to go coast to coast 40 times without hearing the same mp3 once! lol.
Touch screen by the driver is a must have. Size-wise, it would be great to have a huge one but i think for navigation and scrollin' through mp3s, a 7" will do. but then again, a 7" in a big rig is like a drop in a ******* bucket! lol! Im actually mounting a 19" flat panel by the rear seats in my car so my passengers will have something to watch other than my hair! lol