I use mine all the time and DS is 2 and 1/2. I just throw it in my bag with some nappies, wipes and nappy sacks. I just use it under his bum. We have just been overseas, and I used it in the boot of car, on the grass at park, in the parent change rooms, on a friends bathroom floor (wasn't about to stink out their lounge-room, haha), and on our bed.. Pretty much wherever he needed changing. I just use a wipe to wipe it down, regardless of anything touching it or not.

I don't use the nappy bag though, just the mat..