Base scanners in the house are ok in NY, not mobile. The law was recently changed a bit to be even more vauge. If you have a ham license and NOT scanning public safety freq's mobile, your good to go.
Unless your being really stupid or a cop is having a really bad day, most will not bug you on a MV stop. This would not be the time to invoke a roadside 1st-99th amendment debate.
In any case, USE FRIGGEN COMMON SENSE!