quote Doughboy12: "We do it all the time...not that that makes it right but we have never had a problem...but we walk from the entry point to the river. Our car is parked where the permit is submitted but I don't think that matters. The box is just a spot to put the permit. The permit should indicate your entry point...IMHO."
That's basically what I do too. I enter at the point of least resistance to the area I am traveling but put my slip in the closest box. Imagine having a water access cabin on Farm Lake and having to motor (or ski/snowshoe/walk) across, fill out a slip, motor back across, just to enter the BWCA from your back yard...life sure gets complicated sometimes! LOL!