I'd like to hear peoples thoughts on whether you should buy a new car every few years to avoid depreciation, etc OR just keep driving the older car into the ground or until you actually need another car.

I hadn't really thought about it until the missus brought it up yesterday. The Mazda6 is now 3.5 years old, so I'm going to look into what the smarter option could be.

What have you done and what do you think?