Because of Magento EAV design it would be extremely slow to do a search on every field, however you could create your own module that plug into Global Record Search
Take a look at Mage_Adminhtml_Model_Search_Customer
In your config.xml
...
<adminhtml>
...
<global_search>
<matt_car_test>
<class>matt_car/search_test</class>
<acl>matt_car</acl>
</matt_car_test>
</global_search>
...
</adminhtml>
Read more at Adding your custom module to Magento’s Admin Global Search
You could also rewrite the default search and add your custom fields
<global>
<models>
.......
<adminhtml>
<rewrite>
<search_customer>MagePal_AdvanceGlobalSearch_Adminhtml_Model_Search_Customer</search_customer>
<search_order>MagePal_AdvanceGlobalSearch_Adminhtml_Model_Search_Order</search_order>
</rewrite>
</adminhtml>
</models>
</global>