I've been using them since around 2004 when I had some tyres fitted to my old and late lamented Alfa 156. Had them delivered and fitted down the road from work in Banbury ... remember that town name!
Over the years I've placed a couple of orders with them when they have beaten the other...
BlackCircles are an independent network of tyre suppliers and I noticed when I was on their site recently that they have a section dedicated to particular marques, Renault included:
http://www.blackcircles.com/tyres/renault
Might be worth a look if you are looking for a new set of tyres