Don't have any personal experience of them but there are plenty of dodgy outfits along this stretch of the Naas road near The Red Cow.
Anecdotal evidence suggests a lot of cars sold from these outfits may be clocked.
Be very careful.....
I have just looked at carzone.ie and found this dealer. They are an independent dealer and do not appear to be a member of SIMI. Usually when a garage is a member of SIMI, the SIMI logo (blue and white with arrows) appears on their website and this is not the case.