Lately I've heard a buzzing in the back of my car, after I turn it off and take the key out. Think the fuel pump is on its way out?

It sounds like the pump. It should only buzz when it 1st primes when it's been sitting for a while. Best to do a fuel pressure test before you start spending $$.

Cossie

My car exhibits the same symptoms. However, I don't think the fuel pump is the culprit. There is a check-valve in the fuel return line which keeps the fuel system pressurized when the car is off. I believe this is what makes the buzzing on my car. It's been doing it for a long time (more than a year) and it doesn't seem to be a problem. You can see this valve in the rear driver-side wheel well. You still should check your fuel pump, though.