Modeling in Sketchup

Since my last update, i'd been working on modeling for a while. Initially, i chose to build a 3D model in Autodesk inventor, but later i realise it is not an appropriate program for modeling. So, i found another software called Google Sketchup and it works very well but still can't satisfy me.
【i should mention that,because i made a heap of screenshots, i will use some of them to show my modeling process on Sketchup】
The whole works were done in June(it took me a lot of time to learn and use).
                

 Firstly, i downloaded two wheels as a component from internet so that i don't need to make wheels and this will save me as well( wheel is a bit complicated ).Here i draw a rectangle by using pencil tool(you can see it in the large tool set at right side).

 Next, draw a circle and the size of this circle should be a bit bigger then the wheel, because i'm using it to make a wheel housing).

 Use offset tool to draw a smaller concentric circle. Then draw a few lines on the rectangle using pencil tool so that i can cut some unneed parts of this circular plane.

 By using eraser(delete) tool, i've got a very basic part of a wheel housing.

 Move the outer circle on the red axis, a plane will be created.

 Lock the wheels.

 After some modification on wheel housings, i use select tool and move tool+ Ctrl to copy this wheel housing.

 Drawing four lines.

 Here, using Push/pull tool, i create a 3D obeject.

 Then,i draw another two lines.

 There is a plugin for Sketchup called Curviloft, it can create a surface between two lines automatically, by using this special tool, a surface is created.

 Copy（move + Ctrl)a curve from wheel housing.

Using scale tool to get the curve into right shape

 Create planes by closing those lines.

 Repeat the previous step

 Repeat the previous step and create surface using Curviloft plugin.

 Again, i use pencil tool to draw a few lines and connect them.

 The process of building the rear wheel housing is exactly the same as the one of front wheel housing.

 By using Curviloft plugin, i can create most of surfaces i want for making the rear of my car.

 Most of the following steps are all the repeater of precious process i've done.,

 The use of ruler tool can change the position of object choosing a point as the pivot.

 In this step, i draw a few lines to get a surface that has been separated from the main car body.

 Select the surface separated and move it into the car body.

 Then fill the gap by creating surfaces.

This is the final work.I have created a model of my design, which is a sport car. But because this model does not have good quality of reflection of light after i render it in Keyshot, an 3D rendering program, I stop doing this work and start rebuilding a better model in Autodesk Alias. The following pictures are the rendered model.

 You can find that the reflection is not complete,and the shape is not right.