I have never had a problem waiting until the brake light turns on to replace my brake pads. I have even driven several thousand miles to get home before changing them. I usually get about 50K miles out of a front set. Being that there is 10-15% pad left when the light come on it is not an issue to drive many miles to get home. When changing your brake pads be sure the sensor is fully seated or you can have problems. I change rotors every second pad change just as a precaution. If you live where there is salt on the road you need to change rotors every pad change as the rotors have huge amounts of rust on them. Do not turn MB rotors especially if you live in a high-speed area where you might have emergency stops from 100+ mph, like on the German Autobahn.