Hardware

Actuators

I bought these relatively cheap actuators (I first got the 5-wire ones, but ended up only using two of their wires)

Then I just used some thin sheet metal to mount the actuators in the doors and laid their wires to the trunk.

Control electronics

For controlling the door actuators I'm using two relays and for the trunk actuator only one since it only needs to unlock.

The black box is a "Remote Central Control Box Kit" it could probably control the actuators on its own, but I want more control, so I'm just using it to have a pre-made remote. (If you only want Bluetooth you don't need it at all)

For Bluetooth I used a HM-10 4.0 BLE module (I can't find the exact one on amazon.com so here also the German link)

Here is an overview of all the electronics: