It would be better to NOT do them at all, but if you feel the NEED to smoke some tires, DO NOT bounce off redline for more then a few seconds, if even that, personally I do not let my car get that close to redline. Take the burnout opportunity to learn engine/tire grip control, you should be able to "burn" enough rubber off to make smoke while honing your driving skills, just my 0.02.on the m5 would it better to do donuts in 2nd gear or first gear, i find first puts more stress on the engine bouncing off the rev limiter like that. What do you drift, donut, tire spinning guys think about that.