Under the hood, passenger (US) side near base of windshield.
Trunk by the battery behind black felt-like insulation.
E38 2000 740iL Orient Blue
E91 2012 328xiT Alpine White
Passed on to new families:
E30 1987 325i Royal Blue
E39 2003 540i/6 Sterling Gray
R56 2010 Mini Cooper S British Racing Green