Auto-RX arrived about a week ago, I have added product to BMW and Vauxhall 2.0  ( Opel in US ). The Vauxhall has started showing noticeable signs of improvement already, the BMW isn't used as much in comparison, so I think it will take a bit longer with this car. The Vauxhall had numerous oil leaks due to back pressure, the oil leaks have either stopped or diminished to the point of customer acceptability and satisfaction ,also this car was burning oil and smoking through tailpipe, this has greatly reduced, so the bottom line is ,Very happy customer. The BMW customer needs more time in the driving seat, but I am confident he will be surprised with the results,