The O.P. also asked about maintenance records. I keep a 9" x 12" pocket report folder on each car as well as a maintenance summary worksheet. This summary worksheet is for a 2005 GTO, and it pretty much shows everything important to know about the car on just one piece of paper. (I would've bought a new Challenger, but there weren't any in 2005.) Columns A-G are the main maintenance concerns for this particular car, as well as part numbers, ft-lbs of torque, sockets needed, etc. Every car has differing concerns and maintenance intervals, mainly due to make, which decade it was assembled, and options.

Columns H and up are very short summaries of each maintenance session by date and mileage. Data like declining tire tread and brake pad thicknesses in the summary can predict when future replacement is needed by looking at just one piece of paper. For each session, I hand write on notebook paper what I'm going to do, what I did, date, mileage, tread, pads, etc., similar to a mechanic's work order and his notes. I file these notes in date order behind the worksheet summary in the report folder along with important receipts, etc.

Sometimes I put post-it notes on the front of the report folder as reminders or future maintenance needs, what needs to be done in the next session. I also keep notes in my phone on each car, such as photo of accessory belt routing, photo of battery post configuration, VIN, license plate, part numbers for filters, etc. And I keep my report folders on top of the factory service manuals.

As shown, I have changed the oil 19 times, which would be over 30 gallons. It also shows I changed the oil every year except 2015 - a health issue at the same time as a failed clutch slave cylinder requiring the Tremec M6 removal, the removal only listed farther down the worksheet and detailed in my notes along with attached parts receipts. It also shows I haven't driven it much lately... Too busy on my Mopar.