Hi Freddy
This is how i brushed my first time also, so i understand why it looks like this.
here is the problem, what you should have done is kept the original reflections from the car .
CUs the new ones just makes it look fake, you could have done is added the new background in the already originial reflections., the problem you have now is that you added mountains and stuff in the reflections, when there is none of that in the picture
So what you need to do i feel i start over, and keep the basic reflections, but add the stuff u need, also make the bottom of the car darker like you have done here, but do this on the base car. use smudge tool to make the reflections softer etc
the lights and windows does not work at all, they need alot of work ,maybe just keep the orignal ones, and just darken them and add some new reflections.
Its not easy i know, but you learn from your mistakes, but do what i did first time i started, keep doing wrong til u get it right

also work on the same car over and over look at other cars and see how reflections are and how they hit the car in different inviroments .
Hope this helps take care and good luck.
Glac