So im done with the front of the car.
Ill post it soon.
I've started working on the back in this morning.
Base:

WIP:

Comments are welcome.

New WIP picture.
I've started designing the rear bumper.
Not sure what to do with it yet.
I want to add a diffuser for sure. Not sure how it will look like but i will think about.


Till then im not sure if this part surrounded with red looks good.
I got no reference for the rear bumper so im not really sure how it should look like.
Im still learning.



Some help would be really appreciated.
I also think that the black part for the diffuser needs to be more on the left. Right?
Comments or suggestions are very welcome.

You were right - the diffuser does need moving further left:

If you extend the lines from the edges upwards around the body lines, you'll see that there is a lot more space on the right, because it is too far in that direction

As for diffuser design, go crazy, it really can be anything! Just with a diffuser this big you may want to balance out the rear with a larger wing.
Only other thing is that the whole of the paint seems a bit bright - it could use a little more contrast and darkening a bit. Try and introduce some more extreme lights and shadows too.
Good luck