If it helps I'll email you mine. PM me your email address & I'll send it along. I'm not sure how useful it'll be, but it works for me. It's pretty rudimentary...if you know basic Excel formula stuff you'll have no trouble improving it.
Basically, I add two worksheets for each new car I buy..one for fuel mileage and another for everything else...parts, consumables, maintenance items, etc. They then total together & allow me to track expenses per mile very closely. If it'll help I'll leave my data in it so you can see how it works.