That is not so fair to Bogey Jammer is it?
Took the credit when people like the renders and blame him when there are problems....
Shouldn't you be more capable of correcting problems yourself then just replace a skin texture and then click render? So if I say they are good renders, does it mean well done to you or Bogey?
Ambient Occlusion is a visual effects that simulate global illumination shadowing. It has no relation to the physical lights direction / brightness etc. And it does not light up the scene. It is done by calculating the distance of 2 objects, the closer they are, the stronger the shadow will be. The further they are, the softer and lighter the shadow will be.
Ambient Occlusion is mainly used for adding refine details to your render, and believe it or not it is a quicker way to fake Global Illumination.
The way most people use AO is to render it as a seperate pass (a black and white image with just the details of shadows, it renders very quick) then composite the AO layer on your original render in photoshop. Therefore your original render could be done in Default Scanline Renderer without any G.I. process, which will render much faster.
But there is also a downside of using AO. IF you place a light between 2 objects close to each other, they will still generate a harsh shadow between them even though there is a light between them. Because as I said earlier that AO does not react to any physical light at all. Also it does not know the object is solid or transparent, it still can cast strong shadows on transparent object such as glass
You will need more than a few more lights to get an equivalent to a good AO result. (some of the renders here may not represent a good AO)
You will need to create an array of lights to make it like a dome shape. (semi sphere) It is like Skylight in 3ds max.
Even though, this method still won't give the fine and subtle shadow details you get from AO.
You will never run out of new material slots... you can reset the slots.
Materials are still there even though they are not shown in the material slots.
If the wheels spins so fast like that, the car must be travelling. You need to either blur the background or blur the car to create the speed. One or the other. At the moment it just look wrong. The car looks standing still but with spinning wheels. It does not give a speedish look, I am sorry to say.
Unfortunately that only works on Default Scanline Renderer.
Don't think the matt/shadow material support G.I. in Brazil and Mental Ray. It can only generate shadow from proper light, but not from illuminate material (i.e. lighting plane)
One easy way round is render 2 images. one with 'visible to reflection/refraction' unchecked on the lighting plane, so it won't show the reflection on floor. Also make the car invisible to camera. So all you rendering is the floor with reflection and shadow of the car.
Then render another one with 'visible to reflection/refraction' back on the lighting plane, the car back to visible to camera, but make the floor invisible to camera, render that image with alpha channel. So all you rendering is just the car.
Once they are done, put the 2 images in photoshop. The alpha cut-out image above the 1st image.
Another way to do is move your lighting plane higher and, on your floor material make the raytrace reflection with a distance fall off, so the reflection will gradually fade to nothing. (move your lighting plane to make sure it is not inside the reflection range)
Do what Tikshow said in the object properties, but this time uncheck the 'visible to reflection/refraction' instead of 'visible to camera'. Because what you seeing there is from floor reflection and not directly from the camera.
The "brazil doesn't support..." is only not being able to preview in the material editor slot. It does not affect the material and render.
However, I found that annoying though. That is why I prefer to use the standard Mental Ray in Max
Have you check that the headlight texture map is applied underneath the glass? It is difficult to tell if it is transparent or not if the texture map not there, because the inner light area is black.
One way to check your material is to create an object (sphere) between the camera and the car, then apply the glass material to it, then render it out. If it is transparent, then there is nothing wrong with your glass material.
Have you tried changing the colour next to the 'Transparent' to black? As I recall, black is transparent and white is opac (just like alpha channel you see in Photoshop)
I don't know any link of tutorial. However, I have made a quick scene to explain(3ds max 8). You can explore the scene to found out how I did it.
There are 2 parts. The 1st part is made up of 2 objects: the tyre and the side wall(which is a plane object with bend modifier to made it a circle. I did it that way because it is easy to map)
The 2nd part is attached the side wall object to the tyre, wielded the vertices and then apply meshsmooth (or turbo smooth if you like it)
You can see how the 'Mix' material was used.
'Mask' and 'Composite' are simular too.