While you're browsing blogs and various racing sites, save pictures of vehicles that stand out to you! Graphics you like, colors, etc.
As a designer I love seeing pictures of things a client likes. It's a visual representation of what they want. It's a lot easier to take 200 pictures and design one scheme, then to tell me what you have in your head, and me try to guess it.
On my computers, I have files and files of liveries, helmets, suits, crew uniforms, anything. I cannot tell you how many times I've scrolled through them with clients and them been able to find something they like.
-Kyle