I've been working on this program for a while now, and I can't seem to get it to work right.

Classes here

My problem is that I cannot get the cars to stay inside the "grid" no matter what I do. I've tried different methods to do it, the one I have now works "in theory" but I cannot produce the results on screen that I do when I run through the numbers in my head.

If someone could run through it and see if there is a logic error in there or if "in theory" just won't do it with this particular set-up, that would help a bunch.

You don't even have to spell out what it is, give me an idea as to where to begin and I will hopefully will be able to learn more and figure it out my self. Right now, I need some guidance becuase it's got me stumped. Thanks in advance guys!