Now make the extrusion shown and weld vertices in the blue circle.
Chamfer the edges shown.
Now that the interior of the trunk has been made, we can make the hinges that hold the lid on the trunk. The trunk interior has a hole in the bottom and this is not a mistake. The engine which we will make later will fit in the hole. The hinges are really easy to make. Start with a box and extrude it around as shown in the picture. We are not going to put much detail into the hinge because it won't be seen that much.
Extrude a little and scale the geometry out to for a large flat part as shown.
Chamfer the green edges and then delete the red poly.