Without offending anyone, the best car forum I have come across and I now use frequently is http://www.mitsubishiclubaustralia.com/forums/index.php.
I like all it's extra features like the Garage (which allows you to add a car, then add modifications as you do them, where you bought the mods and had them installed etc it's brilliant), Chat, Merchandise section, etc. ALso the "Last 15 Posts" scrolling link box at the top is genius