How do I model this Bentley trunk?

[SwitchedDreams]

I am currently creating a classic-ish bentley, however I’ve run into an issue; I don’t know how to model a curved trunk.

Let me explain.

As outlined by the red lines, this Bentley Arnage has an everso slightly curved trunk that gradually melts together with the area where the rear lights are.

Take this little illustration here too. I want to achieve this look.

I’ve taken too many attempts at this, it’s becoming nerve wracking, lmao. This is what I get.

I can’t seem to cleanly align it with the rear light-surfaces.
Does anyone have any tips on how to achieve the clean and polished look I’m seeking?

Keep in mind I want to have an accessible trunk that opens and closes.

[Hazelfluff]

Im assuming you wish to achieve this without blender?

I would take the image you have and break it up into basic shapes, like an artist or a sculptor would. then you refine the details from there

After that look at each edge and see which ones need to be rounded