Reduce the amount of reflection so your vehicle won't look like it was made by plastic...and it gives you 2 more FPS :)
Install these files in your main GTA V directory
*ENB by Razed
V1.1 gives you another option if it's too matte for you

Cars :
https://www.gta5-hub.com/vehicles/2013-ferrari-f620gt-f12-berlinetta-hq
https://www.gta5-hub.com/vehicles/kia-stinger-3-3-gt-2017-addon-0-5-beta
https://www.gta5-hub.com/vehicles/volkswagen-golf-vii-r-2014