Video drivers are not sending the correct resolution. I guarentee it 100%.
same thing happens to me whenever I mess with the video drivers. My screen doesnt accept 800x600 only 640x480 and 1024x768.
When you set the resolution in VGA mode, it doesnt save those settings just so you know.
The only way to fix this is to boot the computer normally in your car, then unplug your lcd,plug in a CRT (they take a better range of resolutions) and then change your resolution from there. I would then create a restore point right away.