[Jeff]

You can do this but you'll need to use an undocumented Vizard plugin called SceneGraphTools.dle. Here is an example that spins the right front wheel.

import viz

osg = viz.add('SceneGraphTools.dle')

ground = viz.add('tut_ground.wrl')
car = viz.add('mini.osg', pos = [0,0,7], euler = [90,0,0])

# Get raw handle to 'rfr' group node
rfr = osg.getRootNode(car).findChildren('rfr')[0]

# Get handle to children
children = rfr.getChildren()

# Create new raw group node to hold children
tireGroup = osg.addGroup('RightFrontTire')
tireGroup.setChildren(children)

# Insert tire group underneath rfr node
rfr.setChildren([tireGroup])

# Get handle to new group node
tire = car.getChild('RightFrontTire')
spin = vizact.spin(1,0,0,90)
tire.addAction(spin)

viz.go()