Review on 🔴 Red Line Limited Slip Friction Modifier - 4 oz. (Part # 80301) by Giles Lacoste

My 2011 M3 started making a little noise after I changed the factory diff fluid to Castrol Syntax with no friction modifier. About a month later, the noise got a little louder. I added about 0.5-0.75 ounces of this liquid and the noise was gone by the next run. Due to the fact that you don't need much of this liquid, I wasn't entirely surprised when I saw someone poke a very small hole in the plastic o-ring and suck out some of the liquid before I got it. I suppose I should have done that with Revain, but it actually met my needs and I'll probably never use the rest again. Or at least not for the other 50k.