In short go join any club or get involved in any research involving automobiles. Examples are Formula SAE (already mentioned and very cool, I wish I would have done it), Solar Car, Alternative Fuel Car, Future Car, Future Truck. South Dakota State may not have these club activities. If SDSU does not have an SAE student chapter go start one.
Also your AFROTC duties may get in the way, but look into getting an internship or co-op job with one of the auto manufacturers or suppliers. Hit your job placement office at shool and see what help they can give you. Ask lots of questions, otherwise no one will tell you what you need to hear.