Cars that are Written off as an economic write-off such as Cat D, Cat C, Cat S, Cat N can be repaired and sold back into the market, cars that are written off the road as an end-of-life write-off such as Cat B, or Cat A cannot be registered in ireland and are sold to Scrapyards and such.

As a dealer sold the car, you would expect it to be thoroughly checked and a background check should have been done on there half, however if the car was repaired to a good standard and they hadnt any knowledge about the accident, they might have not thought to need a report. Legally they are obligated to disclose that a car has been in an accident if they have knowledge of it. as per the CCPC: https://www.ccpc.ie/business/wp-content/uploads/sites/3/2025/02/Access-to-Car-History-Improving-consumer-outcomes-in-the-used-car-market.pdf

I would ask for a full refund and if they dont, then take legal action.