Looks like there are several other car hire companies at Knock airport. Google 'car rental knock airport' or try this link
http://www.irelandwestairport.com/to.../car_hire.aspx

To the best of MY knowledge, there are NO disreputable car hire companies in Ireland -- though there ARE some less than reputable agencies and agents ...

I have no personal knowledge about car hire at Knock, though. Dooley has a pretty good reputation in that they are the most TRANSPARENT company, when it comes to fees and pricing. If you perform Due Diligence, whilst researching offers with other companies, though, the rental experience can be equally pleasant.
I've used Dooley a number of times over the past dozen years, but I have also used Most of the other companies, as well. The trick to a pleasant rental experience is to understand all the Rules and Terms before committing -- so that you are not 'Surprised' by 'Extra' charges.

See: http://www.ireland.activeboard.com/t...5000-deposit-/

Bob

Budget run out from knock and whilst I havn't rented a car for 5 years I did use Budget at least 4 times a year from 1979 to 2017 trouble free.

Skellig Michael was one of our absolute favorites.

Although there is not much at all to Doolin, we enjoyed our ventures into the local pubs for music.