Many of the more successful businessmen do ride around in SUVs, but more likely Expeditions, Suburbans or Landcruisers (ika nga, "bang for buck") rather than the more ostentatious. This tells their business partners and clientele that they're well-off but not wasteful with their cash. That's a better image to project.
Of course, if you want to project an image, you're not projecting as good an image with an X3, Q5 or GLK... that just tells them you couldn't afford an X5, Q7 or GL... better to get a top-of-the-line Japanese or American vehicle than to settle for a cramped and overpriced German...
