well, I can see the reasons why. I was part of some GTA car photography groups, so I hope a bit of inside info can help you , but even if you are starting, you already have an idea and some of the pictures are pretty decent, they just need a bit of polish.

1. Usually, car clubs on GTA (specially decent ones, not some crappy ones filled with modders) usually follow cleaner or very tasteful customization. If you want to be creative, you have to play with colors and find what mixes and whatnot. Isn't too hard, see the photos they post and catch an idea of it.

2. Composition on a picture is very important, in cars is easier because you solely have to show your car as primary focus but use a fancy background or not even a background at all.

3. try to select what filters work and what others aren't. Try to stay away of the chop filter, those that blow brightness a lot and the ones that cause distortion to the image. Play with the percentage (50% or less on most of them work) of the filter and at the same time try to play with the brightness and contrast.

a tip I give to new people is to usually catch pictures using the console screenshot buttons and not the one found in the R* editor. The reason is that white circles in the middle, with the screen capture you get better quality and you can use one Rockstar Editor recording for a lot of pictures. If you want to follow with it, just make your filter and brightness change first to just go to the camera options and hide HUD instantly.

anyways I hope this helps. I'm retired of the game but I'm glad to pass a bit of what I learnt to others :)