What does this fuel cord thing do??

[Z-Thrizzle]

Located on the passenger side of the trunk by the tail light.

[Randy Forbes]

If the self-locking mechanism (activates w/door locks) fails, you pull the cord to retract the pin holding the gas filler door.

[Z-Thrizzle]

If the self-locking mechanism (activates w/door locks) fails, you pull the cord to retract the pin holding the gas filler door.

Ahh. I didn't know there was a lock for the gas filler door. Learn something new everyday.

[boncovi]

Ahh. I didn't know there was a lock for the gas filler door. Learn something new everyday.

Not on all cars. I wanna say after 4/99 production?

My coupe's gas cap door has no lock. Lock is on the gas cap itself..

[JoshS]

Yes, model year '00 and later has the pin lock for the fuel filler door. Model years '96-'99 had a locking gas cap instead.

[Bear Grylls]

I always thought that was fuel shutoff or something

we had freezing rain a few weeks ago and I thought the door got frozen shut so I lightly pulled on it till it popped open. In doing so I snapped off the plastic peg and just stood there going 'WTF is this thing'

got to love it

[Cloudbase]

The fuel door on my E30 even locks. I locked my key in it one time only to be locked out of the car.

[DYL]

Just FYI, I discovered that the end of the cord on my E36 can be detached and reattached. No need to cut a hole to remove the trunk lining. I imagine it is the same for the Z3.

[Oilburnin]

Yes, model year '00 and later has the pin lock for the fuel filler door. Model years '96-'99 had a locking gas cap instead.

Mine has neither (booo), and coincidently enough, just this weekend realized that my wife's Z4 has the locking door. Thought it was kind of cool, although as mentioned earlier, I don't think it would take too much force to break that locking pin if someone really wanted your fuel or, even worse, wanted to taint your fuel...yikes!

[CMM3]

Whatever you do don't pull it !
It's the fuel ejection valve, just like in an airplane it allows you to jettison extra fuel.
But unlike an airplane it's not for safety in an impending crash, rather it's to shed extra weight when you want to go really fast.

Never noticed if my car has one now I have to go and look.
They are good to know about, I've had to use it before in one of my other BMW's.