I just got the car a few weeks ago. Found this in the trunk and have no clue what it is. This is located on the side of the car where the fuel intake is.

edit: NUTS the links didn't work. I'll update short;y with new pics
edit2: hopefully the pics work this time

edit3: 1998 Camaro Z28 convertible.

 

It would help if you list what kind of car it is and the year? It appears to be a proportioning valve or cutoff valve.

 

Looks like the valve for the convertible top. If you need to put it down by hand instead of using the motor you turn the valve so its possible without messing anything up.

 

ahhh thanks! I don't remember my 1995 convertible having this valve thing, but your theory makes good sense!

 

I own a 2000 vert. Its there on mine too

 

From Shoebox:

http://shbox.com/1/conv_top_pump.jpg