On one hand, I find it amazing that people would intentionally splash mud on their SUVs, or even worse, pay to splash mud on them, so that they can look like they've been offroading.
On the other hand, it doesn't suprise me. I've noticed that very often when I see a 4x4 truck or an SUV with mud on it, the mud stays on for weeks and weeks--often in almost the exact same pattern*--as if it is a badge to be worn proudly.
Now I'm sure there are some people who do go offroading often enough, live on a dirt road, or just don't care to clean their truck/SUV when it may get dirty again soon. However, I highly doubt that accounts for all of them.
Then again, the way the spray-on-mud is mentioned in the text, it seems that it may be used for less-than-legal purposes (obscuring plate, etc).
*This would be a vehicle parked at work to where I walk by it daily.