Clara Market is a weekly affair. Every Sunday from about 8 am until the stuff is sold. It's not a car boot sale but a market with a mixture of stalls selling crafts, salvage, tools, poultry, groceries,clothes and footwear, plants, dvds, modified car stuff, furniture and the divil-knows-what. Some people are there with car boots but are in the minority by far. If you want a pitch, I'd say you'd need to be there by 6 am at the latest.
On the route in (it's not in Clara vilage but on the Clara side of the road between Clara and Moate) last Sunday, there was the biggest Garda and Customs checkpoint I ever saw. Every boot was checked and every diesel vehicle was pulled over to the side of the road and the diesel syphoned and checked for it's colour. I'd say there was about 10 of these operations underway while we passed through the check point.
There are probably lots of these type of markets in Dublin and elsewhere but there's nothing like it in the Midlands/West. I've heard there's one somewhere between Monaghan and Cavan that's even bigger but I'm not sure where exactly. Well worth a visit to Clara for an eye-opener if nothing else.
Rebecca