Savannah and Brunswick are huge car export ports because many manufacturing facilities are spread out between South Carolina and Georgia: Volvo, Mercedes, BMW, Honda, KIA to name a few. These ports are also the largest on the Eastern seaboard of the US. So access to shipping is probably one of the main reasons. Also major demographic shifts to the Southeastern part of the US help supply the labor pool.

Georgia and South Carolina tend to be the poorest states. The Poverty rate is around 14.5% for both. Compare that to California where the poverty rate is 12.5%. Though the poverty rate is lower, California has more people in poverty than Georgia and South Carolina combined. Anyway, using the word "impoverished" is grossly misleading.