To keep a vehicle maintenance log, write detailed information in a spiral-bound notebook every time your vehicle gets serviced, or document the maintenance electronically with a car care app or spreadsheet. File receipts and warranty information in a designated area.
If you prefer a physical maintenance log, find a notebook small enough to fit inside your glove box so you always have it on hand. Enter data about each repair or preventative maintenance service when it happens. Include the date, mileage and description of each service. Log notes about any issues you notice with the vehicle between services, such as a strange noise or a small leak under the car. These notes help your mechanic diagnose a problem should one arise.
Several smartphone apps give you the option of tracking vehicle maintenance information electronically. Examples include aCar, RepairPal and Car Minder Plus. Mobile apps allow you to input various details about car maintenance so you always have access to the records.
Another electronic option is to create a spreadsheet to track care information. Make separate tabs for repairs, maintenance and observations. Input the details as you would with the physical log book. Use Google Drive or save the document to a cloud service so you can access the data even when you aren't at home on your computer.