hmm nice idea but i think the fingerprint reader is used ONLY to log you into the pc
Im not sure they give you any info to be able to read what its said etc.
Also if i remember it be bout 1sec slow or more depending on the pc to stop or start a song.
I do like the IDEA of using thumb scan to start the PC for the cool effect.
Also if someone else was using the car you could set the start sound of windows as Welcome <name> so it says diff name each time someone scans in also you could have diff frontends or diff skins for each person
I like the idea cause no1 would be able to get the pc logged in