Some questions:
1) You only had to replace the ice every other day? That seems like a long time. Even in a cooler, ice takes less than a day to melt/become warm.
2) You mentioned you covered the back windows with black paper. What did you do about the front? Because I looked up 2002 Chevrolet Venture and apparently it looks like this:
Couldn't people peek through the windshield and see you sleeping?
3) How much room was there in the back? Van looks small for an air mattress + cooler + your belongings.
4) You said you removed the rear seats. Did you remove the mounted brackets as well?
5) I had to look up camping potty and I guess it looks something like this:
Where did you put this? It would be pretty awkward to keep it in the front and poop while people are walking by, so I'm assuming you put it in the back. But then there's the phrase "don't poop where you eat/sleep." Even with kitty litter, it had to have smelled. Plus, like I mentioned earlier it doesn't look like there's much room in the back. So wtf.
6) Pics of the van or it never happened.