We used Turo (peer to peer rental) on a recent sit in the US … the rate was about 1/2 of the rental company rates. I checked and found Turo active in the UK with rates in August starting around 33 GBP, but there did not appear to be any Turo listings in Ireland… but perhaps there is another similar platform there?
When rental rates get so high, sometimes Uber, taxis, and public transportation start to look reasonable if you’re not out on a lot of trips most days.
Happy travels!