Open Doors
Note: The trunk of every possible car can be opened, but not every car has interior design!
Change to Transformation Oriantation
Firstly we have to make to Local Mode

First we select the door

Press N to rotate

Press X to rotate around the correct axis
If the doors opens up right or left, we press the Z button.
If the doors opens upwards, we press the y button.
If the doors opens up cross, we press the X button.