Smokescreen

Whether engaged in raging battle or friendly conversation, an ulterior purpose usually exists. Job is to lead enemy astray. Sneaky, but charming and affable... considered most devious yet most trusted of Autobots. In car mode, emits thick smoke from tailpipe... attracts to metal. In robot mode, shoots missiles which wreak havoc on enemy aircraft radar and guidance systems... electro-disrupter rifle shorts out electrical targets.

(Source: Wikipedia)