[OAC_Sparky]

Without going to the car to check myself, to check what system you have, the solution is simple. Jumper or disconnect the trunk switch, whichever you need to. If it's a single wire going to the switch, disconnect it (and tape it) so that it doesn't complete the circuit to ground. If it's two wires, jumper them together or disconnect them depending if the switch is open or closed when the trunk is closed.

The idea here is to bypass the switch to make the alarm think the trunk is closed. The side advantage to this is that you won't have the trunk light coming on randomly draining your battery. The downside is that your trunk light will no longer work.