Okay, so here's the deal!
If you don't post, you won't lose your newbie status. The admins keep their cards pretty close to their chest as to the exact number of posts and length of time on the board necessary before a newbie graduates to junior member. You may find that a little harsh but really the system is just designed to encourage you to participate in the community. I am pretty sure that if you had made just a couple of posts a week over the last five months, you'd already be a junior member and selling parts.
If you are a keen gear head and a responsible and trustworthy person, I can understand that you might be upset when people suggest that they don't want you around, if you are only here to sell parts. However, the fact is that you have been here for five months, you only have 21 posts and only 30% of those are outside the marketplace section (yes, I checked
click) so you have to understand that people 'might' misinterpret your motives for being here.
If you are in this for the long haul, hang in there brother and you'll soon reach your goal. Take a look in the newbie section and see if you can help out any fellow enthusiasts diagnose some problems with their cars. A few more posts will see you right but try to refrain from posts like, "Bump for a good seller!", "Yo Dude! Your ride rocks" or "Anyone got the hook up for JDM parts?" etc.