Some 38 people were arrested in Killarney, Co Kerry, during the first two nights of a car rally. Most of the arrests were for public order offences.
Gardaí were last night preparing for what they expected to be the busiest social night of the weekend with the ending of the rally.
According to course organisers and the Garda, between 80,000 and 100,000 people gathered for the rally, the Ordnance Survey Rally of the Lakes.
There were 31 arrests on Saturday night and a further seven people were arrested on Friday night. Most of the arrests were for late-night public order offences and five were for drink-driving.
Sgt Ray Walsh, Killarney, said tens of thousands of young people were in the town on Saturday night. Two Garda dog units and a number of custody vans were in operation. A helicopter had also been employed in traffic management during the rally.
Sgt Walsh said there were no serious assaults.
The fire brigade fought a blaze at the Glebe car park in the town centre where a vehicle had been set on fire. Gardaí suspect the car was specifically brought to be burned out during the rally, and they were examining it forensically yesterday.
The 16-stage rally took place across some of the county's most dramatic and scenic routes and several routes, including the Ring of Kerry, were closed for much of yesterday. The event is worth an estimated €25 million to the tourist town.
Former world champion Colin McRae drove a course car and was a major attraction to the rally this year. All accommodation was booked out for miles around.
The rally attracts thousands of "souped-up" cars which are showcased by their young drivers.