I saved that out as a .jpg then I removed the gradient section and used the Heightfield to normal map Effect to create a normal map .... bring the bumpiness down into the .5 area ...then saved that out closed Paint.net and opened Wing3D. ....
... A little on Wings3D ... I love this program but it can be buggy so I'll try to clue you in to those bugs as we go .... right click on the main window and choose a cylinder and then save the file .... wings auto-saves the file but if you don't give the file a name it can't and then will crash on you .....

Then with you're cylinder still selected right click again and choose Scale, the wheel will rotate on the X axis and be facing the Z axis Y of course is up and down. Scale down uniform, then scale axis x until its nice and thin .. then hit the (Spacebar) to deselect all .... <-Remember that one ... when you get fast you'll use it constantly. Now click on the Polygon Mode (second from the right) and select one of the circle sides,right click and select Mirror. You'll want to scale down in object mode again then (spacebar) polygon mode .. select 1 polygon this time a square on the outside of the cylinder ....  then press (I) (<-remember this)!! to select all similar ... should have all the outside of the cylinder selected now. I know this is long winded but Once you learn some basic keyboard shortcuts and a few tricks your modeling will just FLY !!!! anyway after both sides are selected we'll choose Extrude - Normal, then drag the mouse out a bit then left click. with the sides still selected, scale x outward, Extrude again, then Extrude one more time and scale inward ... you should see your wheel taking shape now. (Spacebar) Deselect all then select the Circle sides, right click and choose Bridge ....... whoa the middle dissapeared !!!

Once you have your Chart colors choose continue ..... Project Normal. for simple shapes and pre-made textures this works better. The next window will open up with your model on a horrible colorful alphabet background. Close that window for now, from the [File] menu on the top choose import image .... and go the the texture ...... then from the [window] menu open the Outliner and you should see your texture there. In the outliner choose the [m] material- should be cylinder_auv or something, its not the default because we uvmapped already, anyway right click and delete the ugly texture. Now, to add our new texture, select the texture image and choose "Pick up Image", then select the [m]material again and choose "drop Image" and it will give you a choice. Put the texture in the "diffuse" and put the normal in the "Normal". Now select the model and choose UV Mapping and the second window should open again this time with our texture in it !!!!

by now you should have a good idea about how wings3d works and how to find your way around the interface .... so get the tread right and I'll continue with the tips and tricks ... like jumping between selection modes, try choosing an outside vertex, press I, then jump to edge mode, then polygon mode, notice how your selection keeps adding up ... very useful for uv mapping, and In the main window for modeling as well. Also I should mention the undo ctrl+z, However to undo again its ctrl+alt+z, and thereafter is also ctrl+alt+z. You can also set the amount of Undo's to hold onto in the Interface Menu,
click the little Icon that looks like a little window in the tool bar to open it up.

Next we'll use a N-Gon ... whatever that means ... for the spoke. This is a 5 vertex double-sided flat pentagon. You'll need to rotate z 90 ... then select ONE SIDE ONLY... and extrude. But here select "EXTRUDE - then RIGHT CLICK "NORMAL". This will extrude each side separately, but evenly, instead of building another pentagon. In many of the option you can right click and get even more options, some are hard to understand and others quite helpfull, something else to play around with.. Back to our wheel, you should extrude about a third out and then repeat that twice more, playing with the scale in-between, you can also switch to vertex mode and try rotating for a more "Krull-for anyone who's old enough to remember" look. Once you've Extruded out all the way to the rim, Use "Move-X" to shape the wheel, most car wheel spoke inners are rounded. Here's a good place to use the Jumping between selection modes to add the next section.

From here I'm sure you can Model the Hub and Brake on your own, so continue on. But I should talk about modeling and game modeling. You may have seen software like Zbrush, 3DSMax, and Poser that can go into millions of Polygons, "paint" on your model, use Ray Trace lighting. And you may have watched movies like "Avatar" and seen how much can be done in CGI. And I agree those images ARE fantastic!! But what they didn't show you was the room full of networked computers pumping out render's for about a half a year to make it!!! Game's are made just the opposite. We want to use the least amount of verticies and polygons and rely mostly on out textures to do the magic. Understand when playing a game, your computer is trying to figure for every vertex (address in space) of every frame for 25 fps, 30 fps, 50 fps and make changes according to the camera's position, meanwhile wheels are turning, heads are bobbing, arms are swinging, not to mention the subroutine on contact, additional sound, additional explosion graphics. Try doin the math yourself.......

Now, to Export you're model for 3DRad, In object mode, select all objects and choose combine, then do a "flip - x". For some reason Wings3D exports to Directx backwards, that is words on you signs and stuff will be backwards if you don't. It looks wrong in wings3d but will look right in 3drad. I don't have a better explanation .... just do it. Then export your .X model, save your work, and save a screenshot (tools menu) to make a thumbnail with, and exit Wings3D. Open your screenshot in Paint.net select a nice square around your model cutting most of the rest of the image out, and hit ctrl+shft+X to crop to the selection, then resize the image to exactly 128x128 jpg and save it out...