It also depends on how much / what you use the vehicle for and how well you treat it.
We currently have two vehicles. My SUV gets used very little (short work commute) and I don't ask much from it. So even though it is 12 years old and needs a LOT of little things, the motor is currently sound and it should pass inspection and is owned free and clear.
My wife on the other hand treats her vehicle a little rougher and it tends to burn through clutches and brakes more frequently. It's a little cheaper to keep her in a newer (leased) vehicle that stays under warranty and swap out when the lease is up. I hate the thought of having a car payment constantly, but the lease is a cheaper payment than buying, keeps her out of the repair shop and she can get a new vehicle every 3-4 years.