The wheel warning is causes from you having 2 foliageBendingNodes defined, but under Lizard and Goodyear wheels you are referencing an index 3 node, which isnt defined. <foliageBendingModifier index="3" minX="-2.17" maxX="2.17"/>..
just change every instance of
<foliageBendingModifier index="2" minX="-2.17" maxX="2.17"/>
<foliageBendingModifier index="3" minX="-2.17" maxX="2.17"/>
TO this
<foliageBendingModifier index="1" minX="-2.17" maxX="2.17"/>
<foliageBendingModifier index="2" minX="-2.17" maxX="2.17"/>
or define a third foliageBendingNode