I had previously calculated how off my speedometer was, so plugging in, securing the wires, and doing the initial calibration took me all of about 6-7 minutes. I've seen some yota people run the boxes into their cabs, but the boxes are weather resistant so I didn't bother. If you do want to adjust to .0X of a percentage you'll need to run it inside as those adjustments need to made while moving.Also have one of those yellow box things....mines just been sitting on my desk for two months. I've kept convincing myself that it's going to take at least an hour, looks like I've been wrong. How much back and forth did it take to get the calculations right?
Next time I went on the freeway I brought my speedo up to 80 and using a gps app saw how close I was (within 1/2 mph). Adjusting took literally 1-2 minutes.