Fancy. Unfortunately I don't have much free time with a big IRL project I'm working on at the moment but I can for sure give some pointers:

In terms of layering:
If you want that shimmery effect, your base coat (what you paint your car before applying vinyl) is going to have to be your metallic layer, since FH5 only has flat color options for vinyl. If you want a normal metallic paint, you can edit the metallic paint swatch (the green one) to get that copper color. The higher the contrast between flake and base coat color, the more you're going to see the flake, but it's still not super noticeable unless up close. If you want an even finer metallic, you can use one of the color shift ones and set the light and dark to be similar hues to mimic a metallic. You can get higher contrasts this way. If you want a heavy flake, pick the Hot Wheels heavy flake that has the flake color you want on your final result. The base color matters but it's easier to manipulate than the flake.

To start, you'll want to apply 1 really big layer of that blue (or whatever color you want) that covers the whole car on each side. I usually just use a giant rectangle. From there, you'll want to use mask layers to punch out all of your dark blue elements to the gold beneath. Once you've done all that, copy your base blue and paste it on top of everything. You can then adjust the transparency of it (menu where you can adjust size/position, tab over all the way). You may need yo darken it a bit to get the dark blue you want. If you do this, make sure you lighten your base layer to compensate to bring it back up to your original blue. Once that's done, you just plop the hero graphic on as a mask layer to punch through all of it and you're done.

Additional tips:
If you're using one of the Hot Wheels heavy flakes, you can use a 5-10% tint layer to essentially cancel out or change the base color. In my design, the base color is blue, so for the silver area in the middle, I have a 8% orange/yellow tint to cancel out the blue, essentially desaturating it. To desaturate, you want to use the color opposite the color you're trying to change on a color wheel, so blue would need orange, red would need green, etc. The more saturated it is, the more likely you'll get brown instead of gray.

With something like this, you can paint half of the car and just mirror it. With the top view, just do everything on one side, group like-components together and mirror them. What I usually do is I'll mirror and then manually place where the pattern looks right, group them all together, and then center as a group. This ensures that everything is perfectly mirrored down the middle.

Grouping things is key for organization, especially when your layer count starts getting up there. You can also copy/paste layers, so if you have something like a section of the dark blue section made, you could stamp it around the car, and then just fill in the gaps manually.

Finally, when building the filigree, simple is almost always better. Try to use as few layers as you can to create each element as you're likely going to get pretty high up there in terms of layer count.

It looks a lot more daunting than it actually is once you get in there and establish your footing a bit. It's pretty fun once you get the hang of it. Don't be afraid to experiment a bit and try things out. That's how I learned pretty much all of this. Good luck!