i'm not sure if you were asking for this advise, but on shiney ... think of a morrior as the most shiney surface. should be easy cause i think that's true

... the point is that shiney describes what the surface reflects - a mirror reflects so much that you see exactly in the mirror what real life looks like. paint wants to be like a mirror but it just never makes it that far. However, it's pretty close when it's good. that means reflections are sharp and clear, but the color of the paint. using just gadients will never work. hard lines suggest shine/reflection. the least reflective surface might be a black piece of paper. all you will see is a gradient from grayish, where the brightest light is hitting it, to black where the least light is hitting it. so a mirror reflects every spec of light and color, and as you step down in shiney then you only get the brightest colors or the brightest light. you also lose clarity in the reflection (think of orange peal in paint). so flat black isn't shiney - on a car it might be semigloss even, but you got this effect on your car with a simple gradient and no hard lines. other paint looks shiney with the use of hard lines ... gradients really should only be used to show color shifts due to the paint reflecting ambient colors/light. a red metalic car may just be red but because of the clear coat and the metalic, it picks up bright light and reflects it all over the place.
these are just things to keep in mind when you try to achieve a certain look. for an indoor/3D look, notice giant blocks of white as if there are lights in the room and nothing else. what this does is show massive reflection but NOTHING else to clutter the paint up like concrete, or stripes on the road, trees over head etc. 3D art is like a photo of a car in a black room with white, perfectly placed lights - hard lines that bend with each curve make the paint look flawless and glassy ... almost wet.