I'm sorry but I don't agree, even if it's for Z related items.
Why? because a minimum of "background" should be there for possible buyers to check. I bought a few second hand items from people in the US Z forums for example, but always checked how many posts they had, what they posted, and how long they have been members for.
Many, many conmen and fraudsters out there, just read the US Z forums, for example. It's like Ebay feedback (but not as effective, unfortunately). A minimum of regulation needs to be in place, to safeguard the more naive of our members, as some people would assume that since a person is a registered member, he/she is automatically worthy of being trusted.
Admittedly a car is possibly harder to sell fraudolently, but still, imo a little regulation is needed.
PS: come on now, don't take us all for fools, amongst the reasons you listed why you are advertising here, you forgot to add that it's free and selling to a private you'll get more money...