Every single thing I do to any of my vehicles gets logged into a spreadsheet. Included is date, miles, work done, part with number, cost and comments if needed. EG: lifetime warranty on shocks or brake pads along with where I bought the part. Invoices for parts with a LT warranty are in my file cabinet. In the rare event a shop does the work I name the shop. I have spreadsheets dating back to 5/7/88 when my 88 E-150 got it's first oil change with 1,000 miles on the clock. Older vehicles were deleted. I had written logs in each of the vehicles I owned which I kept on a spreadsheet when I bought my first PC.