I beleive there is no relation, barring that Renault owns a bit of Nissan, and Nissan owns a bit of Renault. I beleive the new Micra will use the Clio platform though when it comes out in a few years. The Clio, as it stands, is substantially bigger than the old Micra - which has been out for like 8 years or something now! If it used that platform, it'd be using a platform almost as old as the 10 year old one it was replacing hehe :-) The old ClioSport chassis though, is now the new Twingo!