The Dynamique Plus was the regular Dynamique with higher spec (air con etc) - there were no exterior differences.  The "+" name has been dropped now and Dynamique buyers can choose from six option packs instead.  The "+" didnt have rear discs as standard - only 1.6, DCi 100 and Renaultsport models have them.  
The reason its called a Clio Sport Dynamique is because its part of the Sport range (also Elegance, Freeway and Renaultsport ranges).  
My parents have a Dynamique on order, with the order sheet calling the car a "Clio Sport Dynamique".  Its obviously not a Renaultsport car though!
One thing that puts me off the modern 172/182 range is the fact that the Dynamiques look so much like them.  There are obviously differences, but its not like the old days when I had a Mk1 1.2 - there was no way you could confuse it for a 16V or Williams with their fat arches and bonnet bulge.