last week i went to my local autzone to check and see if they had any german castrol syntec. they did and 0w-30 was labeled in red and it said made in germany on the back. well today i go into the same autozone to buy the oil, but today there was only the 0w-30 labeled in yellow and it didnt say made in germany. so i went to another autozone only to find they stock the yellow label 0w-30 and they had only on red label 0w-30, but it did not say made in germany on it. so my journey continues to another autozone, where i find they stock only the red label 0w-30, but it does not say made in germany anywhere on the bottle. it only says made in the usa from domestic and imported components. so i bought 6 quarts hoping its the real deal. so which is the real german castrol syntec? how can i tell if the red label 0w-30 that i purchased is the real german syntec? thanks in advance.