I drive car wagon with a large spacious rear area. I limit my shopping trips, I buy in bulk.

You have to be very disciplined to get as efficient with Amazon. It's probably not really possible.

I have 6 neighbors in my cul-de-sac. The Amazon truck probably visits 5 out of 7 days a week. I never worried about whether my Amazon purchases were wasteful based on trucks and fuel. They were quite wasteful in the sense that I bought a lot of cheap crap I didn't actually need.

This is the worst thing about it. Holding something and deciding if it's worth your money is a much longer process than clicking "buy now", and you've probably don't even remember doing it when the goods show up in front of your door.

Just shop with a list and don't break the rule of not buying anything not on the list.

Amazon day is probably similar. There's a designated day of the week where they deliver everything I've ordered that week. I don't have hard data, but it makes sense that if more than one person in my building/block/etc does the same (thus sharing the same delivery vehicle), it's probably less driving/gas overall.