6. Know when to move on. At a certain mileage point expensive cars can become "hot potatoes" due to the costs of maintenance/repairs. You see a lot of $15,000 BMW 7 series for sale with no takers. Because a major engine or transmission failure would nearly total the car.
#6 for sure. I had bought an Audi new in 2003 and as soon as I hit 50K on the odometer I traded it in on something NOT GERMAN. The coverage provided for the first 50K miles really saved me thousands, yes thousands, of dollars. Fuel pump went out twice, front headlights had to be replaced three times and the sunroof would open of its own accord, especially during driving rain storms. The dealership would always give me a copy of the invoice of what it would've cost me if I hadn't had the coverage and that opened my eyes. As soon as I hit 50K miles I traded it in on a Lexus IS350.