I made an excel spreadsheet to document everything. There are categories such as Modifications, Gas, Payments, Tickets/Legal, etc.. everytime I buy wax, change oil, pay a ticket, or decide on a part I want, it gets documented. The list under modifications with "$0" in the total spent block is very long lol. But it's good to put down what I plan to get and once I get it I fill in that block and color that row as "complete". There's a grand total block that adds up the totals of every category showing exactly how much I've spent on the car since I bought it.