Primefaces component not refreshing - jsf-2

Question

I have been looking at Primefaces 3.4.2 since IceFaces 3.2.0 has too many issues. I have a dataGrid of vehicles which are contained in a panel. I have an add button and each vehicle panel contains a remove button.
The add works fine; it adds a new vehicle panel each time. The issue is when I delete a vehicle, the panel is removed, but the value(s) remain. For instance, if I have 3 vehicles with the year as 2008, 2010, 2012, and then I delete the first vehicle, you'd think you would see 2 panels remaining with the year as 2010, and 2012. Instead, I see 2008 and 2012. The backing bean is doing it correctly and I do see the correct values if I manually refresh the screen. Now that I have presented my case here's the code:
<p:dataGrid id="vehicleGrid" var="currentVehicle" value="#{vehicleInfoBean.getVehicleList()}" columns="#{vehicleInfoBean.getVehicleList().size()}" styleClass="vehicleInfoPanel" rowIndexVar="rowIdx">
<p:panel header="VEHICLE ##{rowIdx+1}:" style="width:100%" styleClass="textEntryInputTable">
<h:panelGrid columns="1" style="width:100%" styleClass="vehicleInfoPanel">
<ui:include src="../components/vehicleinfo/vehiclecomponents.xhtml">
<ui:param name="currentVehicle" value="#{currentVehicle}" />
<ui:param name="labelOnly" value="false" />
</ui:include>
<div class="deleteButton">
<p:commandButton value="Remove" label="Delete Vehicle" action="#{vehicleInfoBean.deleteVehicle}" update=":vehicleInfoForm:vehicleGrid" process="#this">
<f:setPropertyActionListener value="#{currentVehicle}" target="#{vehicleInfoBean.currentVehicle}" />
</p:commandButton>
</div>
</h:panelGrid>
</p:panel>
</p:dataGrid>
Any ideas? I have tried all sorts of update values including #form, but it's all the same. I haven't used a dataGrid before but I need the iterative capabilities that ice:panelSeries has.
UPDATE: Here's the code in the include:
<h:panelGrid columns="2">
<p:inputText id="vinInput" styleClass="stdFieldControl" value="#{currentVehicle.vin}" label=""
required="true" requiredMessage="VIN is required" >
<p:ajax update="#this vinMsg"/>
</p:inputText>
<p:message id="vinMsg" for="vinInput" errorClass="ui-state-error-text"/>
<p:outputLabel value="-----OR-----"/>
</h:panelGrid>
1/14/2013 - Updated code
<p:dataGrid id="vehicleGrid" var="currentVehicle" value="#{vehicleInfoBean.getVehicleList()}" columns="#{vehicleInfoBean.getVehicleList().size()}" styleClass="vehicleInfoPanel" rowIndexVar="rowIdx">
<p:panel header="VEHICLE ##{rowIdx+1}:" style="width:100%" styleClass="textEntryInputTable">
<h:panelGrid columns="1" style="width:100%" styleClass="vehicleInfoPanel">
<p:inputText id="vinInput" styleClass="stdFieldControl" value="#{currentVehicle.vin}" label="" required="#{empty param['vehicleGrid:0:btnDelete'] and empty param['btnAdd']}" requiredMessage="VIN is required" >
</p:inputText>
<p:message id="vinMsg" for="vinInput" errorClass="ui-state-error-text"/>
<p:outputLabel value="-----OR-----"/>
<h:inputText id="yearInput" styleClass="stdFieldControl" value="#{currentVehicle.year}" label=""
required="#{empty param['vehicleGrid:0:btnDelete']}" requiredMessage="Year is required">
</h:inputText>
<p:message id="yearMsg" for="yearInput"
errorClass="ui-state-error-text"/>
<div class="deleteButton">
<p:commandButton id="btnDelete" value="Remove" label="Delete Vehicle" action="#{vehicleInfoBean.deleteVehicle}" update="#form">
<f:setPropertyActionListener value="#{currentVehicle}" target="#{vehicleInfoBean.currentVehicle}" />
</p:commandButton>
</div>
</h:panelGrid>
</p:panel>
</p:dataGrid>
The add code looks like this:
<div class="addButton" style="padding-left: 2.17%; float: left; clear: both">
<p:commandButton id="btnAdd" value="AddVehicle" label="Add Vehicle" actionListener="#{vehicleInfoBean.addVehicle}" update="vehicleGrid"/>
</div>
Instead of putting the check on the buttons, I decided to set the required attribute of the components referring to the buttons. This code works if I hardcode the iterator index. For example, required="#{empty param['vehicleGrid:0:btnDelete']}". This code points to the first delete button in the panelGrid. What I need is to dynamically derive the index to this - required="#{empty param['vehicleGrid:#{rowIdx}:btnDelete']}". The add button was easy since it doesn't reside in an iterator. How do I code the param in a way that I can dynically refer to the rowId of the panelGrid? The RowId looks confusing but this is coded in a way that each Vehicle Panel is displayed next to the previous panel. The row in this case can be thought of as a column. Anyone have any ideas?