Agree with Mark, on my old e46 M3, it would do exactly 170 (GPS indicated 163) on the the A2 Autobahn when I lived in Germany. The engine note changed slightly and it would not go faster (held it for 10-12 seconds, numerous times). Clearly the CSL's areodynamics are slightly different and has slightly more power, but I use it as an example of how the BM limiter doesn't kick in on an indicated 155 as you would expect.
