The 20 minute conversation about transmission oil that saved my car

I thought I knew enough about cars to handle a simple transmission fluid change on my 2016 S6. Bought what I thought was the right oil online and was about to do it myself in the driveway. At the last minute, I decided to call a shop that's known as an Expert Audi Oil Specialist Sharjah just to confirm the spec. The guy on the phone spent 20 minutes explaining why my plan was risky – different friction modifiers, different viscosity ratings, the importance of the correct additive package for the DSG. He didn't even try to sell me on bringing the car in, just genuinely wanted to help. Turns out the oil I bought was completely wrong for my car. I ended up taking it to his shop and watching him do the service properly. He even showed me the difference between the correct oil and what I had bought – the color, the smell, the viscosity. I'm so glad I made that call. Anyone else almost made an expensive mistake by assuming all transmission fluid is the same?