What is better to buy?

An expired or expiring domain or a new fresh one?

What do you have to look for when buying an expiring or expired domain?

Between an expired and a fresh one, depends on what you want to do with it. If it's just an auto-blog then you want to look for backlinks and keywords in the name. If it's for a legit site then you want it to be brandable.

As for expired domain shopping, I look for age and backlinks. DO NOT worry about PR! I'd say 90% of the time the PR is fake or will drop anyways when ownership transfers. You can get lucky with a PR6 domain occasionally but don't rely on it.

I would buy older domains obviously. but it has to have some backlinks to it and the site url hopefully has to have some kind of keyword in it that gets searched a lot. new domains take longer to get going

thanks for the info fellazz!

if the site already has backlinks like WHOIS, it will be fine