As I haven’t received any replies I kept digging and sort of solved the problem, but not in an elegant way IMHO.
What I wanted in vehicle’s view.php
<?php $this->widget('bootstrap.widgets.TbDetailView',array(
	'data'=>$model,
	'type'=>'striped bordered condensed',
	'attributes'=>array(
		'id',
		'vin',
		'vehmake.name',
		'vehmodel.name',
		'vehtrim.description',
		'license_tag',
...
where ‘vehtrim’ is a parent, ‘vehmodel’ is a grandparent and ‘vehmake’ is a great-grandparent of ‘vehicle’. I though I could access the last two directly by defining a relations() using ‘through’, but it appears that ‘through’ only works forward (HAS_ONE/HAS_MANY instead of BELONGS_TO).
What I ended up doing in the vehicle’s view.php:
<?php $this->widget('bootstrap.widgets.TbDetailView',array(
	'data'=>$model,
	'type'=>'striped bordered condensed',
	'attributes'=>array(
		'id',
		'vin',
		array(
			'label' => 'Make',
			'value' => $model->VehicleMake,
		),
		array(
			'label' => 'Model',
			'value' => $model->VehicleModel,
		),
		'vehtrim.description',
		'license_tag',
...
which required changes to the vehicle model:
...
/**
	 * Gets this vehicle's make
	 * @return string vehicle make.
	 */
	public function getVehicleMake()
	{
		return TVehmake::model()->findByPk(TVehmodel::model()->findByPk(TVehtrim::model()->findByPk($this->vehtrim_id)->vehmodel_id)->vehmake_id)->name;
	}
	/**
	 * Gets this vehicle's model
	 * @return string vehicle model.
	 */
	public function getVehicleModel()
	{
		return TVehmodel::model()->findByPk(TVehtrim::model()->findByPk($this->vehtrim_id)->vehmodel_id)->name;
	}
Is there a better way? Suggestions are appreciated.
Thanks,