You are trying to model an extremely difficult exterior. This is a Satoshi Wada design. Audi have a massive design buget and the world's best designers, so surface sets are really sophisticated.
He has worked with Satoshi Wada at Audi AG and taught me a tremendous amount about modeling really high end surfaces. He has produced videos on modeling the complete car. IMHO. you need these and his valuable feedback and advice.
If you can't afford several months of tuition, then you can enroll for 1 month at a time and he will allow you to watch all 50+ videos on the A5 Sportback.(Even just one month would be very rewarding)
IMHO. if you want to reach Automotive Alias entry level and get a great job, you need to put your hand in your pocket. I am sorry if that sounds harsh, but it is what it is!
okanawa, thanks for the advice. but this place from Graham looks not so as in Audi (for example, edge the hood does not go to the beginning of a-pillar, but "diffuse").
These are imgs. from the Phase 1 model. The A5 is built in 3 phases (see www.learningalais.co.uk where all this is clearly explained). Students take on more and more difficult solutions as they progress and on the phase 3 model which I have built it is to a very high std. The student that built this model is now working for one of the biggest car manufactures. He is an Alias Digital Modeler. (BTW. on the phase 3 you build these difficult transitional srfs. from scan data. You can't do it from blueprints)
I too have done very well. I tried for a long time to reach a good standard on my own, but it isn't possible. I studied with LearningAlias for several months and I learned more in that time than I could ever have done working on my own. I am too embarrased to tell you how many years I wasted working on my own.
The only way you can learn good Automotive modeling is with a good teacher. If I wanted to learn a musical instument, I'd pay for lessons, because it's the only way to make fast progress and avoid waisting loads of time. A teacher give you knowledge gained over many years.
Perhaps you are special, but whatever the case, I wish you good luck.
Here's another vote for Graham's tuition, for me it gives me a reason to keep practising. I have someone I can't let down. On my own I'd probably quit as soon as that surface over there untrimmed on me for no reason, or I delete a surface and I can not undo that, or I get continuity on one edge and lose it everywhere else or I try to use freeform blends but the c-o-s doesn't have a good parametrization on it so it skews like a drunken soviet! (dont worry though, it is always your fault in the end, you just got to learn your mistakes)