Further info and a quick update

I did contact the Gardai, other driver failed roadside breathalyser and was arrested on suspicion of drink driving. He wouldn't speak to anyone or get out of his car. He refused an ambulance and walked out of the car when the Gardai took him away. I took loads of pictures and took a video of the scene.

I've reported the incident to his insurance company this morning but the Irish office is closed until Monday so spoke to UK office. Left details and they said someone would be in touch Monday.

My own insurance contacted me this morning after me reporting it last night. They explained the situation and said that I have two options;

1. Claim through my own insurance. They will send the car to their approved repairer. They will complete the repair (and/or get it assessed as to whether or not it's a write off) and they will claim back through his insurance company. My 'No Claims Bonus' will not be affected and will go down as a 'not my fault' claim (paraphasing). They will also claim back the excess I need to pay and any increases to my insurance premium for next year.

2. Claim from his insurance. Cons are that if they dispute my claim, my car will remain unrepaired until such time agreement is met. All the while, I am liable for car rental costs, storage, etc.

This is all new for me but at the moment, I'm leaning towards dealing through my own insurance. It gives me better bargaining power and in essence, it's for help with incidents like this that I've paid them handsomely over the years! Also, I would very much prefer to get the car fixed so I don't want to have to battle with some assessor. Although if I need to, to remedy the situation, I absolutely will hunker down and fight it to the bitter end. It is my pride and joy after all!!

Thanks to Conor and JohnH for the quick replies. Really good advice there, much appreciated.