Child support arrearage

I have a 12 y/o son whose father lives in Alabama. My son and I moved from Alabama to NC four years ago, and his father and I were never married and never had a formal custody/support arrangement. He agreed to pay $300/mo and did so until this past July. I sent my son down to visit for a two-week summer visit and he filed a fraudulent ex parte temporary custody order in the courts there, claiming he couldn’t find me. Once I found out what happened and we went before a judge (he gave them a non-existent address for me and used my maiden name so I was never served), my son was immediately returned to me (and now wants nothing to do with his father, but that’s another issue). He last paid the $300 in June 2010. I have retained an attorney here in NC for the custody issues, but in the interest of saving money (knowing he won’t agree to anything and will likely try to drag it out in the courts) I am going to let CSE handle the support issue. With regards to child support arrearages–will they hold him responsible back to July? I anticipate the order will be for at least double what he was paying, using the calculator. Can he be held in arrears for the difference prior to July, and if so, for how far back? He tends to have a substantial amount of under-the-table income, which I realize will be difficult to prove, but it involves buying/repairing/reselling vehicles at a profit. If I can show he has over a dozen vehicles registered in his name at any given time, will that or any other property (he also has two houses, one is waterfront) be used to determine his income? Thank you!

Arrears date back to the date the court action is filed. Property is not considered income, but can be used as evidence of the same.