The woman, in her 20s, remains in critical condition.
Scarlett Faulkner was airlifted to University Hospital Limerick following a brutal attack on the R494 at Birdhill before being transported to the specialist head trauma unit in CUH.
Gardai are continuing to investigate the assault that took place on Saturday, March 21 shortly before 5.30pm.
Gardai are appealing to anyone who may have witnessed this incident to contact them.
They are focusing their investigation on the movements of two vehicles, a grey 62 Ford Transit van and a blue 161 Volkswagen Touran people carrier between 4.30pm and 5.30pm.
Gardai believe the vehicles to have been driving dangerously or in a convoy around the Birdhill area, including Cooleen, Crag Cross, Shower Cross, Kylebeg, Annaholty and Thornhill.
Anyone who may have footage of these drivers are asked to provide it to An Garda Síochana.
Gardaí have asked that any video footage of the incident circulating online not be shared on social media platforms or messaging apps, but instead provided to investigating Gardaí.
Anyone with any information is asked to contact Nenagh Garda Station on (067) 50450, the Garda Confidential Line on 1800 666 111, or any local Garda station.