Hello there!
I decided to jump in this contest, even though I'm really a beginner. It will test what I actually learned from the first hard surface modeling tutorial.
After some hesitation, I decided to go for a futuristic Hover-Car.
Here's the starting blockout (that is still ongoing, of course).
My god I'm going to get crazy!
I've beenworking for a pretty long time now on a smoke effect on the hovering part. It was nice and baked, and I just adjusted the settings. Now, for whatever reason, the baking that took 20 seconds now is not progressing anymore, and I can't find what I accidentaly changed that make baking impossible.... Gaaaaaah!
Daaaaamn! That really was a pain to do... It's not exactly how I imagined it, I'll see later if I can tweak it...
Some changes to the scene.
Small issue now with this change is that the front of the car lose some white nice reflection, that I'll try to tweak with "studio lights"
And I realise that this smoke is too dense maybe, now...
Probably my last WIP post here before I go into 2 small details I want to finish.
Today was tweaks day, trying to take in count what was said during the critique livestream.
So time has been mostly use to tweak lights, the car material and.... That's pretty much it.
Final things that need work : Headlights, steering wheel, and small tweaks neer the door interior. 
Oh, and just because I find it funny : This is the current lighting setup : 
The small black square is for unwanted reflection. :)