Again with this? No, the show was not raciest. I don't think the characters were either. The flag panted on the car is a prodomantly negative symbol often associated with racism and founded in treason.
General Lee is actually still regarded as one of the best Generals the US has had (despite him not fighting for the USA in his later career). Nathan Forrest, Stonewall Jackson, and James Longstreet are also Confederate Generals who are well regarded as some of the best this nation produced.
No one is stopping anyone from putting the flag on their car, shirt, belt buckle. I don't care one bit. That is your own choice, and your own property. Still is a negative symbol, and I can tell you that any time I choose.