as my (ex) wife's $20k garbage can. That was a long time ago. Now I'm sure it would be a $30k garbage can or whatever. But frankly my wife was the worst offender. Half the garbage was hers. My kids learned to follow that example. They didn't ride in my car a lot because I mostly just drove it to work but when they did I didn't provide them things (e.g. fast food) they could leave in my car or I made sure they took anything with them.

In your case, if it doesn't bother your wife it's not going to bother your kids. They probably spend more time with her and ride with her more often. I feel like unless both parents enforce the same standard the kids will follow the more lenient option.