Well I will tell you this. I was at the Audi Sport factory last year and to my knowledge only the DTM was built on the same production line as the RS4. Hence why the DTM also got the Sprint blue colour option and never the normal Sline as well as small things like the S4 suspension set up even thou a lot say the Sline is the same as the DTM suspension its actually 10/15/20mm lower. And there is a few other things to mention.
Personally I say they had left over paint from the old rs4
But the way to tell is if your car has GMBH stickers or engravings all around your vehicle, IE under the bonnet on the bar code, inside the door sills, on the fuel cap. Then you know for sure it was.
But hey I could be mistaken about the Sline bodies being built in Audi sport. But I know as well the BUL engine was built on the normal production line, but it had development of the motor was from KTM and AUDI RS.
Yes you read right KTM.
