I was thinking also of the Renault Symbol indeed. For the 1st generation, the development history is unclear and I couldn't find any source so far.
The 2nd series is everywhere stated to be a teamwork of the Renault R&D centres in France, Turkey and Romania (the then brand new Renault Design Central Europe centre of Bucharest). The sources I've found are not much detailed and precise, but it seems that the lead role is to be acknowledged to the French Technocentre, and this could be confirmed by two facts:
- the Renault Design Central Europe of Bucharest was opened in 2007, so I guess they hadn't much possibilities to work on a project scheduled for 2008 (maybe it was the contribution of some Dacia engineers?)
- I couldn't find any precise information about the Turkish R&D centre, but according to the Renault website, the Oyak-Renault joint venture doesn't do R&D activity (so maybe again a contribution of individual engineers working at Oyak-Renault?)

So I believe that the considerations made for the Symbol II can be valid also for the (Clio) Symbol I: a French origin flag appears to be the most probable, although the models have never been sold in homeland France.

Obviously no doubts for the 3rd series and its replacement Renault Taliant, being simple rebadgings of the corresponding Dacia Logan series.

But at this point another question is: who designed the Renault Fluence? Renault-Samsung in Korea or Renault in France? Maybe it was already specified in other topics, but it's still unclear to me