You could make those wheels what I'd class as the "easy way" as there's a nice small gap between the spokes.
Create the centre cylinder with say, 20 sides.
Create an outer rim tube with more sides, say 40 and 3 height sections.
Select groups of 3 polys around the edge of the cylinder (ie: leaving 1 poly between each group).
Using the 'extrude' tool, extrude the selected polys to the required length of the spokes to meet the outer rim. Do this in about 3 or 4 extrusions so you have some vertices / edges to play around with to create the concaved appearance.
Select the vertices that make up the end of the spokes (at the rim end) and use the 'scale' tool to create the spoke angles.
Select the middle 2 rows of vertices around the rim and use the scale tool to move them towards the outside edge of the rim leaving maybe an inch (relatively speaking). This'll be used to define the width of then inside area.
Select the polys that now make up the inner band of the rim tube. Use the scale tool to close them inwards creating the inner "dish".
For the central hole, I'd create a cylinder the diameter you want and long enough to pass through the centre of the wheel entirely. Using the 'boolean' tool (see the help file), cut the cylinder away from the wheel (will create the center hole).
Using the boolean method again, but this time with spheres instead of cylinders, create the countersunk areas for the bolt holes (if you create one and then clone it and move the pivot point to 0,0,0, you can then use the rotate tool to get the correct circular shape fo the holes).
Again using the boolean method as you did with the center hole but with much smaller diameter cylinders, create the 5 holes for the bolts.
Some time to tidy up / create the rim edges nicely with extrude / bevel tools and should be good to go
Disclaimer: This was typed up off the top of my head so hope it's easy enough to understand and correct.. but have used this method before for my own wheels (actually the ones in the XRT pics above were done this way but rather low-poly / no meshsmoothing).
a better description with images of the above method