PERFECT!
I added a _cm_pre_getData function to my vehicle class and everything works as expected:
function _cm_pre_getData ($where, $where_array, $fieldarray=null)
// perform custom processing before database record(s) are retrieved.
// (WHERE is supplied in two formats - string and array)
// $fieldarray may contain full details of the current record in the parent
// class, not just its primary key.
{
$pattern_id = getPatternId();
switch (strtolower($pattern_id)) {
// may need to change the contents of $where
case 'list2':
// alter key
$where = str_replace('organization_id=', 'owner_organization_id=', $where);
break;
default:
} // switch
return $where;
} // _cm_pre_getData