Been thinking about car pc (im a PC engineer). I can tell you pc beats iphone/tablets in every category. Also my pc boots faster than any tablet. SATA3 with SSD destroys anything in a tablet. laptop/pc's cold boot in under 5 seconds. Resume in less than .01 Also windows8 is very touch friendly, using now and is great.
Dumb question, can you get hd audio from a tablet? I know androids have HDMI but can with their integrated cpu/gpu can it output DTSHD/Dolby HD? I'd love to be able to run 7.1 in my car.
Also, I run my whole home with computers and media center. Nothings better than $6 a month for Time Warner cable card and having all 1000+ channels with unlimited DVR and 3 channel HD recording anywhere in the home. Also with Girder, or other Home Automation, you could easily open your garage door automatically when you hit wifi and close when you leave wifi. options are endless and no restrictions like with tablets