When you say off road parts do you mean racing parts, or parts for sale?
If you are thinking racing parts as in working for a racing team, having gone down that road (several times) I have two pieces of advice:
1) Don't. There's nothing cool or romantic about working 37 hours straight to prep the car and then fix the damage from testing only to have the driver wad up the RF corner of the car 3 minutes into the race. The Pit Lizards aren't all they're cracked up to be. Oh, and track dogs for breakfast are funny once, only.
2) If you ignore #1, make sure you have your credit card with you at all times (the one NOT maxed out). This is so that when have had it up to <font color="red"> Here </font> with the BS & lack of sleep you will have a way to get home.
If you insist on going racing I suggest that you find a local team and volunteer to crew for them. That opens up doors like nothing else will. If it is specifically off road racing you want into, you might start by clicking the link in my sig file.
Know that if you find a position with a big name in aftermarket parts that more than a few of them think that they're doing you a favor by hiring you into their industry. Read: They won't pay you what you could earn in a field maybe not so romanticized, like designing toasters. BT, DT - MIGHT have learned from it.