I recently purchased a 1991 Acura Integra LS.  In the process of getting it ready for winter, I discovered a lot of water in the spare tire well.  Not good.

After sopping it up, I went to 2gic.com and searched for likely causes.  Among the common culprits are: 

-sunroof drains that are plugged or disconnected

-antenna drain tube that is plugged or disconnected

-bad weather stripping around the rear hatch

-a gap between the taillights and the body

-bad gaskets around the compression vents.  (The compression vents are vents visible in the rear trunk area, and on the leading edge of the taillights.)

A visual inspection showed no tears or separation in the weatherstripping, and the gap between the taillights and body was tight.  So it was time to dig deeper.

I did some more investigating, but nowhere could I find photos of what to look for.  So, armed with a camera and a phillips screwdriver, I set to work.

I chose to start on the passenger side, and it is the easier side (the fuel filler is not in the way).  The first step is to remove the panel over the speaker.  It is held in place by 3 phillips screws.

Once the screws are out, the panel just lifts away.

Then, with a good light, I looked down, and the hose was clearly visible.  And even more clearly disconnected.  I just reached in and fitted the upper part into the lower part.  Super-simple.

I looked to see if there was anything else to do, but it seemed good.

The other side was a bit harder because of the fuel filler.  I had to remove more of the cover, but the result was the same: a disconnected sunroof drain hose.

While in there, I also discovered that my power-antenna drain was not connected to anything.  There wasn't a lot I could do about that because the previous owner removed the power-antenna and replaced it with a fixed one.  I will seal up the opening for that, too, and hope this does the job.