The dome lights in the hatch and roof are controlled by both the doors and the rear hatch.  The lights in the doors are only activated by the door switch.   It is a common problem when the hatch latch begins to wear for the dome lights to stay on even with the doors closed. To test this push forward on the dome light to put it in switched mode (unless some one has turned it around), close the doors and then go back and push down in the rear hatch. The dome lights should go out.

There is no adjustment for the rear hatch latch to compensate latch wear. The only real cure is the replace the plastic portion of the upper latch.

Remote Hatch

The electric hatch release is located in the bottom portion of the hatch latch.  It operated by sending the motor through a 360 degree cycle.  A fin attached to the motor pushes the plastic tab in the upper hatch forward causing it to release from the bottom latch.  A spring in the lower latch pushes up on the upper latch and causes it to clear.

This is a good system but a number of things can go wrong with it.  The most common is the plastic tongue in the upper latch wearing.  As it wears the hatch does not close tightly.  After a while there is enough play in the latch that the fin on the motor can not push the upper latch far enough forward to release.  If the plastic tongue on the upper hatch is worn - replace it.

Alignment is also critical to proper operation.  

If this is the case I will bet that your hatch release does not work either. The culprit is the plastic catch in the upper portion of the rear hatch lock. These are designed to wear and are available from the dealer and probably DEVEK too. If you look closely at the plastic potion of the latch you will see that a groove has been worn into the edge. When ordering the plastic latch be sure to get the rivet too as you will have to drill out the old one.

Probably less than $10 in parts and you get to fix two problems in one - how often does that happen on a 928.

This is a common problem. There is supposed to be either a rubber gasket or some sealer under the hinge. Some windshield sealer will work well. Sometimes when the hatch is removed for repairs it will be replaced without any sealer. The same is true of those little ends that hold the roof tracks on.

You can leave the pistons in place and remove the bolts to a single hinge at a time. This is better done with two people but can be done with one. Remove the two hex bolts on one hinge with the hatch up. Be sure you have good pistons and they have the proper clips holding the ends on. Push up on the area around the loose hinge to create a small gap. Use a caulking gun to put some sealer on the surface below the hinge. Reattach the hinge with the bolts and tighten up. Use a rag to clean off the excess sealer. Repeat on the other side. This will insure that the adjustment of the hatch remains the same - to guarantee that the hinge does not slip you can scribe it first. I scribe all adjustments before I remove them.

3M makes a sealant for this purpose that works great. www.kondratyev.com/porsche/windshield.htm

You can use household products but for some reason they do not hold up on cars.