I've seen the ZGM on a 745i fail for (presumably) no good reason, car wouldn't get out of limp mode until unit was replaced (has to be new, 850$) and coded (an hour labour).
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2002 TiAg M3 6mt
deoranged, dechromed, led tails, ZHP knob, UUC SS v3, GROM, OEM 220M 19's, Michelin Supersports
2006 YZF-R6, bunch of go-fast stuff