Snitches Get Stitches
No matter what, don't rat out a fellow member of the club, regardless of what kind of unsavory business with which they're involved. It's not uncommon for Hells Angels to get arrested and questioned by authorities. If one club member rats out another club member, the rat might not make it home.
Always Pull Over for Police
If one member is pulled over by the cops, it is customary for the rest of the gang to pull over in solidarity. This shows that the club acts as a unit, in addition to being an intimidation tactic if the police start to get a little handsy.