Welcome to our support forums,
miahGTA
Well, all the fields are easy to customize. You can do that in admin panel. The answer to your question - it depends...
There are two forms of it. You can create additional fields for you account aka dealer or use this fields for each auto.. It is you who decide how to use this.
For say you create these fields for account - but his car can be located in a bit different place.
If you create these fields for auto ads - you will need to fill in address each time when you add a new auto ad.
You can easily configure this yourself in admin panel.