Thanks for the quick response. I'll plan to pick up 2 i/o lincs.
I was hoping to get the Dakota installed--had it hooked up (set up was pretty simple) and tested (seemed to work perfectly without having to tweak sensitivities or anything). But, it arrived here just in time for a big cold front, and I couldn't bury it (I tried). So, I disconnected it and will wait until the ground thaws. I'm looking forward to programming some interesting and useful responses to cars coming and going. BTW, not sure why you're interested in the plus, but I learned that having the two sensors also helps reduce false signals as the algorithm is looking for the proper activation sequence (ie it won't go off if both sensors fire simultaneously)--not sure how much of a difference this makes, but if so, it sounds like an added benefit.