Hey man, this is really looking good. I know you're still working on it but so far, I think you doing a fantastic job and is looking pretty accurate. If you keep this quality of work up, you'll have a really nice model when you're finished. I'll keep an eye on your progress.
P.S. How did you find an interior to fit so well? Is it from another z4 car? Anyway, for a first work, you're really doing an AWESOME job! Keep it up
Don't be satisfied with what you can do but rather strive to do the things you can't do!