Welcome to SMCars, I hope you'll enjoy your stay here.
Really nice of choice car. Are you modeling 550 or 575 ?
The hood bulge need refinement, the air intake too. Where the front bumper and the front fender meet, the edges should be curvy and not straight like now. The same for the sides of the front bumper, just below these edges. The center part, at the bottom of the front bumper, is way too ahead. The headlight shape is unclear.
My definitive advice : try to work each part at a time. Don't rush like you're doing now. I think it's not your first car, because there is some modeling skills here. But you waste them by working too fast.
If you're going for accuracy, and many seek accuracy here, you should slow down.
EDIT : I just understood you're the guy from
www.blendpolis.de. I saw your work when looking in the referers statistics from my website
Pixels or Atoms ?. I can't read / write / speak german, so I didn't posted on blendpolis.de. Please tell them I can give support for my tutorials if needed (english / french only)
PS : By the way, nice to have a new Blender head here too.