I just keep a piece of copier paper in the glove box. When I'm done, I write down what I did, the date, and the mileage. Any work done at a garage I throw the reciept in the glove box too. I do keep track of my gas mileage by zeroing the trip odometer after a fill up, and seeing how many miles was on the gas it took to fill it, so it comes out totally exact. I just figure it out, but don't right anything down.
