Are they're any additional expenses/fees to use a car rental for travel from Dublin to Belfast?
Just the usual tolls and gas if you bring it back to Dublin. Plus another couple hundred bucks if you leave it in Belfast.
It takes about a couple and a half hours to drive between the two.
You know that cdw isn't included in the basic rental price and your credit card won't cover it anywhere on Ireland, right?
Just an fyi: I recently found out that my Chase Visa Disney Credit Card does cover CDW in Ireland (since 11/13) However you have to put the rental on that Chase card and they will put a 3 thousand euro hold on your credit card till the car is returned. We are renting a car next month from Dan Dooley at Shannon Airport and there is no additional fee for taking the car into Northern Ireland.
there is no additional fee for taking the car into Northern Ireland
Correct, but a cursory look on the Dooley web site for a random week in June shows an extra fee of about $190 if you drop the car in Belfast.
There is a toll, I forget where it is on the M1, but really just make sure you have insurance on your rental when you go up to Belfast more so if your up there is during parade season June-July.