im far from being an expert but, the tires dont look like they're touching the ground plane(in particular the front ones). dunno what options vue gives u but, maybe try a spotlight for good shadows and then another light w/ omni properties at a low intensity. thats my $0.02 ^^ but its looking good other than that issue.

This is gonna sound weird, but go into ALL of your textures (double-click the icon when you select the object), click the Effects tab, and change the opacity to 0%. In real life things don't have an opacity on their own - they REACT to light. Then, with all of your lights, including the sun (just click on the sun in your information bar on the right side), and change the softness to 10% or more, and change the colors of your lights (double click on the color box at the top) to slightly yellowish orange - or whatever color you're going for - again, in real life lights are not actually "white - they have a hue of some sort and white looks artificial. Feel free to add more lights to fill in shadow areas, and when you do, click on the little "star" in their information section, and disable "lens Flare" - otherwise you'll get this little glow of light in the middle of your shot and won't know why or how to get rid of it. Good luck - on a side note, your comp and models look great!

The shadow on the ground looks strange. What I usally do, is set the shadow strengh to 75-80%, and add 3 to 5 % softness to the light. Your shadow looks too grey to be a shadow; althoug shadows are never 100% in real life, especially with natural light, yours looks too washed out. true, the tyres seem to be floating; to avoid this 2 options: add a few fill lights or change the sun position. You didn't tell us which version of Vue you are running, that would be good to know. if you're on the Vue 5 line, you can use Global illumination, which will compute a lot more accurately the spread of shadows in your scene. If you're on Vue 4 line, add fill lights.

I like your subject matter... :-) This is a very good image. There's a lot "right" with it (as opposed to "wrong" with it), but here are some ideas that might help. You might lighten the texture for the tires a bit and/or make them a little more complex. Tires are rarely this deep midnight black unless they've just been cleaned and armor-all'd... Even then, the running surface will be more gray. Also, you might alter the road surface a bit... A concrete road surface would be lighter, asphalt would be darker. Gravel might average out around this tone, but it would need more bump and form. That, with the lighting tips above, which should make the shadows darker and more diffuse, should make this sort of shot even better, I'd think.

Great POV here, i like all the reflections - well done