Mudd I hope I am not coming across pedantic....but are you sure these were not mink you were seeing?
Firstly pine martins reside in wooded areas, forests, etc. They mainly come out to hunt, roam and rummage at night. They are extremely elusive and shy mammals!
They are considered Ireland's most rare mammal.
So to have encountered 3, in daylight hours,roadside, over a very short distance in the car strikes me as odd and unlikely.
Apart from the fact that they are protected by the Wildlife Act, I personally think they are beautiful and fascinating creatures....so to even suggest hunting them