gotta get this old girl up to snuff, some friends are coming in.

we haven't driven this car for a while but the last time we did, we
started to notice a gas smell in the cabin.  It comes from the trunk
area, and though it's been sitting a while, the odor hangs around the
car like bad vibes.  opening the trunk you get a big whiff...

where should I look first?  I'm an experienced mechanic type but I
don't know this car very well yet. I know there's some experience on
this board.  Thanks in advance for any suggestions.

elijah