Those seem to be the regular 5.1. with the lightening package as seen by the groves. Like you said, Trak Spec. Does that answer your question?
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2010 E93 M3 / MS Catless X-Pipe / AA Catback / Vorsteiner Vented Hood and Bootlid E93 Trunk / ADV1 7.1 Wheels GB / LS3 LED Lights / Harrop Supercharger
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