I have to admit, I've often wondered this. On some other forums I moderate on, private messages are easy to deal with. 

If you get one that is profane, you simply report it. It gets forwarded to the mod team for review and we deal with it. 

Truth be told though, this forum is extremely basic in nature which is why images, etc. must be externally hosted to preserve bandwidth, there's no private messaging, no categories except the main open forum. It seems to work ok for what it is, but the I.T. expert in me certainly imagines what it would be like with more features.

I'm fairly sure Scotty wants to keep things simple though, so it is what it is. 

Because the goal of this site is to ask for car help publicly.

If we had messaging, then I would have to start dealing with complaints like

"so and so was calling me bad names on your private messaging system. Make him stop"

I'm definitely glad we don't have that.

If you want to message privately with someone then give them your facebook or whatever and chat somewhere else.