My rental car stinks-literally

My car went into the shop today for the 6 day repair from my collision. I picked up the rental this morning, a Kia mini-van (don't remember what they call them). This morning it was a bit cool, and so I didn't notice a problem, but as the day has warmed up, the interior has developed a lovely urine odor. I called the rental agency (probably shouldn't name them directly, but suffice it to say, they pick you up) and asked if I could swap. They don't have another van and won't until tomorrow, but they did offer to re-clean it. You know, clean the windows, and vacuum the interior. Because those are the two methods best known for removing a piss smell.