I'm a pretty good waffler, but you've gone back and forth on this for days. I've read your thread, and unless I'm missing something, you should just pick what works.
My XW lives about 3 miles from me so distance isn't necessarily an issue. She has the kids 50% of the time, and when she does, she drives them to school, the store, drops them off at my place. If she drops off, I pick up, and vice versa. I don't pay for her gas or insurance.
What is convenient and fair? Pick that, and tell her that's what it is. Then move on. Unless she has some compelling reason why it'll hurt her, just do it. Be fair but firm, and when she throws a fit, let her get over it.
