Are the majority of Foreign National Tourists in Ireland living in the North?

I am just trying to get an idea of the number of tourists arriving in the South of Ireland using car ferries at ports such as Dublin and Rosslare. Trying to get a handle to assist in answering some comments on this thread.

Anyone been on or lives close to a ferry terminal might know.

It is being suggested that most of the foreign registered cars driving around the South are actually being driven by people who live in Northern Ireland.



Thanks