Thumb car starter is bad. Computer needs to be running to work. which means computer needs to be controlled possibly by the key.....hm might work. Use the ignition switch to turn on computer but disable the starter part of the ignition switch. use a lpt or usb relay controller to start the car. Means you have to wait for you copmuter to start before you can start your car. Make sure you have a computer power supply that can handle engine crank. Since it would be starting the car after its been powered up. Or you could use a pda with thumb print reader.($500+). i'm not sure thumb print readers are ready for cars yet. If you didn't need the carputer to be running to use it that would be great. Then the thumb/finger print reader could power on the car and computer. Search the forum im sure alot of people have already talked this to death.