I agree.
When you have a large PR like this, here's how I like to get it reviewed.
1. Give reviewers sometime to become familiar with the PR. They might not understand all parts of it, but they should have at least a cursory understanding of the PR.
2. Have a meeting where the PR is explained in front of the group of reviewers. The reviewers will understand the PR better and they can ask questions in realtime.
3. Let folks review the PR after the meeting in case they spot anything else, or think of additional questions.
Most of the time PR review is done asynchronously, but doing most of the review in the meeting can also be a decent team building exercise.
Sure, I think it is an odd line. In this case car ownership is a proxy for geography. You could probably find some other interesting proxy variables for geography, that could be used to write 500 word articles. A proxy variable that is in interesting from a monetary perspective could be something that you could use for contextual advertising. I saw four our five car ads when I skimmed the article.