Go to the Trailers panel and press the 'New' button. In the dialog, 
enter a name, identification code (for automatic binding), description 
and custom fields. This information is shown in trailer's tooltip, and 
used in reports. You can upload an image for the trailer which will be 
used to show the trailer in the list and on the map. It is recommended 
to upload square images in order their proportions not to be altered. 
Properties of trailers are the same as those of 
drivers.