Do you know where current model BMW speedometer sensors are? I am getting wider tires for my F30 335i. I want to select a size that will impact my speedometer the least, so I am shooting for diameters that are +/- 1.5% of original. However, I may fudge on this if the speedo isn't measuring speed from this wheel. Do BMWs takes speed readings from all four wheels, or just the front or rear wheels?