Colorado vibration around 3000rpm in most gears

Like Rob Fox (Carsguide, February 14, 2014) I also have a vibrating 2013 Holden Colorado. Mine happens at around 3000 rpm in most gears. My dealer told me that they test drove two other vehicles like mine and that they did the same thing, so it was normal for this vehicle. Thanks to Rob Fox I am a lot more confident now going back to Holden with what I believe is the problem. If Rob's vehicle is a manual he should maybe check out the clutch.