S3 Trunk Solenoid Mod to Unlock

Just modified my S3 trunk lid solenoid to both lock and un-lock.

Fairly simple, requires a small bolt, a nut, two washers and a slight bend in the solenoid actuator rod.

Looking at the lock mechanism from inside the trunk (with the lid open, duh), you will find a slotted metal linkage with a round metal rod linked to it horizontally. The rod comes from the solenoid (to the right as you look at it) which is wired parallel to the door solenoids. The length of the slot and rod prevent the solenoid from unlocking the latch.

To make it unlock, just find a small bolt that will fit in the slotted piece of metal. In my case, a metric bolt and nut that were laying in my tool box worked great. Put a 1/4" flat washer on the bolt, thread it through the slot, add another washer and nut on the back. Tighten the bolt securely in the left-hand end of the slot. Then, carefully bend the rod coming from the solenoid in a manner which will shorten it about 1/4-3/8".

Operate the door locks. You should find that the trunk now un-locks and locks with the doors. If not, adjust the rod length by bending or move the bolt slightly.

I too installed the little bolt in the trunk/boot unlock slider, but now I'm having second thoughts about it. Any thief who has access to the inside of the car can operate the driver's side door master lock. They then have access to the boot/trunk, which is where you might have your valuables hidden. Without the little bolt installed, you can leave the ignition key with a valet parking attendant without any worries.