I am modeling a Nissan Z GT500 car model and I have this problem on many parts of the car I don't know how to solve.
I want the "ducktail" part of the car to blend in the main body panels smoothly, but the best I can do is:
I get these nasty wrinkles no matter if I use edge crease or reinforce the edges with other edges. I know the it looks horrible with several tri-gons and edges too close to each other hence I ask for help. Auto smooth just makes everything 100% sharp but that's not how it looks on the real car... This is done with Subdivision modifier with Levels Viewport set to 1.
I include a .blend file to examine the problem better: https://drive.google.com/file/d/1ducLKRLXFEehvo_y1gVKfDBUpnFpFBar/view?usp=sharing
Thanks in advance for your help!