Zenithal Highlighting on Rhinos

I've been experimenting with my airbrush, and have begun applying zenithal highlighting/shading to my vehicles beginning with my rhinos.  Although still new to the technique, it never ceases to amaze me how quickly I can achieve the results I desire, and how easy it is.  The airbrush is the ultimate force multiplier for the 40k hobbyist; the below results took a total of about three hours total to complete on my four rhinos, and and to apply the initial dark angels green basecoat on two predators.

Here's an example of how the rhinos are coming along:

Applying that sort of shading with a brush would have taken me all day for each vehicle.  Now I need to begin all the detail work, and then its on to weathering.  The job is not yet done yet, but is coming along nicely, its heartening that I will be able to complete my vehicles in a reasonable amount of time, and move on to something else.  I don't feel so bad about spending twelve hours on one tac marine now...