Any time I want to take the car to the RDS and don't want to pay for parking, I generally find free parking around Herbert Road and then walk down Serpentine Avenue to the grounds.
That worked for me for the Springsteen concert, and T4BB.
I think most of the parking pay and display finish at 6.30 so anywhere around Clyde road to Herbert Park should be OK as well. Maybe someone can officially clarify that they are not any later than 6.30 ?
Update : Morehampton road is PAD till 6.30 as is Herbert park and any surrounding streets. Anywhere behind Kielys pub is PAD till midnight so be aware if you go that far.
Its on the corner of Simmenscourt road and Angelsea road and is a nightmare to get into and out of afterwards. Better of parking in Donnybrook if you're coming in that way
I think most of the parking pay and display finish at 6.30 so anywhere around Clyde road to Herbert Park should be OK as well. Maybe someone can officially clarify that they are not any later than 6.30 ?