WHAT........I would like to hear A LOT more on how you plan to do this. VERY interesting. As for the 3rd lane. Just go get yourself a digital lap counter and steal the censers. Used if you can. I got mine for about 15 pounds shipped.
Not sure if I understand you correctly now that I have read your post #6 a few times. You want the PC to control the cars in analog mode? Through the digital chip? You wanting to control speed and braking? If I am understanding you correctly you will have your hands full implementing this on everyone else's track here on this forum.
Joel