Or get decent rock sliders. Many of us don't exactly appreciate the looks of mud flaps.I'm surprised they let you test drive there. It's also a good test to assess the salesman. Did they try to BS their way out if it or did they readily admit you might want to get aftermarket mudflaps?
So you don't learn the hard way, get removable mudflaps. When in very rough terrain it is possible to get a mudflap wedged between a rock & the rock rails moving forward and between the ground and the tire in reverse. If either happen the mudflap will get ripped right off no matter how durable it is. Of course, that's when you want the functionality of a mud flap the most so it ends up being a judgement call at all times.