i have the deici 130's very nice speaker but can seem a little harsh sounding at times . Only problems you'll have are;
1 getting the renault unit out unless you have the right keys, but these can be bought from halfords
2 getting the new pioneer to click into the single din slot due to the clio wiring loom behind the stereo ( i used a small length of string fed through the holes on either side to gently move the wires which slotting the unit in)
3 removing the dash to fit the tweeters properly, unless you attach them to A pillars. Theres a guide to remove the dash if you search.
4 Getting fresh wire to the mids is a bit of a nightmare need to remove several things ( bonnet catch, plastic cover, doorcard and door loom adapter and be handy with a drill and silicone sealant)
5 Dynamats the easiest thing on the list tbh pretty easy heatgun and some patience.
6 if you re amping the diecis getting cable through the firewalls quite tricky but very doable, they run a low RMS though so i dont know if its worth the hassle as the pioneer probably has quite as good output suited near enough to the Hertz
Hope this helps mate good luck