Originally Posted by Triple_Se7en
Write oil, filter and mileage down somewhere and keep UPC receipts that detail what you bought - plus where and when must be visible on the receipt.
Just about every manufacturer has a website that you can store your information. I know Hyundai and Kia has websites I keep stored info-in.
That's not the point though. IF the new owner of the car knows about these online resources they will be able to track down this maintenance data, but it is probably not reflected on the CarFax report and that is what is trumpeted as the valuable car history.
The receipts and handwritten or computer derived notes are most likely the best way. When the car is sold, just hand everything over.