A club member has found the location of the "Coming Soon" "Miami" Service Center. It is located at 3851 Bird Road, Coral Gables, at the corner of Bird Road and 38th Ct.
It will be located in a development that also houses the Gables Auto Vault. Another club member has been informed that Tesla will have the first two floors for service needs and possibly the third floor for vehicle storage.
Here's a vicinity map: