Modeling an old car trunk.

Here is the picture.

I want to model just the trunk, my issue is that I cant get the trunk right. Right at the top of the trunk I used a 1/4 cylinder and angled it down. But on the sides where the door ends it goes from cylindrical at the top to straight I cant get that if that without using a wicked lot of messy vertices. If that makes sense. Any advice.

I’m a bit confused as to how/what you’re doing. Can we see some pics or a .blend file?