MAKS, your Buggatis are too bright at the picture 2. You need some color corrections & Dof via AE (PS would be too intensify for me) to achieve the photo-realistic renders matched with the BG.
I notice in a milliseconds that the ground was sliced for the pic number 2 as well. Lol.
Anyway, the renders of your cars looks terribly COOL!
Sorry for kick some advices like a PRO crap concept artist... but your concept characters (esp the female) looks goin to fall (the side or rear view).
Good luck, mate. And Godspeed!