Trunk wont close all the way down.

If the trunk is latching and can't be pulled open unless you turn the key to release it, the latch is working properly and nothing needs to be opened. Once latched, a failure of the pull-down mechanism to pull the lid down the last inch is usually due to a problem with the built-in switch, or a blown fuse. The switch is what tells the mechanism the trunk has been latched and it's time to pull it down.

With the latch released and the lid up, out of the way, you can use a screwdriver to mimic the striker on the bottom of the lid to trick the mechanism into latching and puling down. You can usually see the switch or at least cause it to activate. If you're lucky enough to see some minor sparking in the latch, that suggests the switch is trying to do its thing but has corroded contacts that aren't turning on properly. If there is no sparking, clicking, groaning, buzzing, or any other sign of life, a blown fuse is a better suspect.