New figures show four in every 10 appeals against clampers were upheld last year.
Motorists having proof of payment and inadequate signage are some of the most common reasons for a successful appeal.
The National Transport Authority dealt with almost five second stage appeals every day last year.
The Irish Times reports that the NTA is hiring additional staff to deal with the volume of appeals coming before it.
"What does it tell us? It [the four in 10 figure] is a little high but this will probably normalise," said Conor Faughnan, Director of Consumer Affairs for AA Ireland.
"I think this will establish at some sort of sensible level - probably lower level then it is at - and I think once it does, that will be a good thing for everybody."