Some suggestions: use high quality logos and don't enlage them, that makes them blurry. The skin might be ok, but blurry logos just ruin it. Some places are ok, like the number on the door and the boxes next to it are sharp, but some are really bad, like the background for the hood repsol and the big repsols on the sides.
Also, you should make a reflection map, because right now your skin is too shiny. Depending on the color it determins how shiny and reflective or matt the livery is.
Red channel controls reflected brightness when light shines on it, Green is reflection clarity (0 is matt and 255 is glossy) and blue is the amount of reflections. You don't have to go into channels, just pick a color using the RGB sliders. If you wanted a matt finish, you would use something like R=10, G=30, B=110 which is a dark blue color.
Here's an example: map for the left side of the hood is dark blue which makes it matt, on the right side it's white which makes it very shiny and reflective. By playing with these you can achieve different color finishes for different parts (like the base could be semi-gloss and the decals matt). The default maps often are greenish white, which makes them too shiny
You can see the reflected trees on the right side and that it gets very bright where the light shines on the blue part above the grille vs a much more even finish on the left
Here's how it looks just for the hood. The easiest way to make a map is to copy your skin PSD file, change the name accordingly (usually just add _map at the end, but check to make sure), and recolor the layers