First I bought a bottle of fish tank filter activated charcoal, some 3/8" - 1/4" tubing, a few 1/4" brass fittings, some JB Kwik, two brackets, two 3"-5" plumbing hose clamps and a quart-sized paint can.
Next, I drilled a hole in the lid and the can.
I then glued the fittings in from the inside and filled the can with the charcoal pellets.
I snapped the lid onthe can with the above orientation.
While I was waiting on the glue to dry, I pop-riveted the brackets together. I later expanded the 90 degrees bracket to be a little more obtuse.
I bolted the bracket to the existing hardware in the trunk.
Next, I cut the vent tube off just a few inches from the filler neck.
I then ran the tubing as seen above. The bottom tube runs to the original exit hole, but sticks out a bit further.