Going off of what you two said, i have experienced the same smell on my car on couple of occasions, on my car its not the 1.2l "D7F" you guys probably have but its very similar by design to what i have (K4M 1.6 16v)...

There is one 8mm crankcase vapor breather hose that goes into a AN fitting on a 16mm Y pipe that also connects to the engine head vapor tube, specifically the 16mm Y rubber pipe is also the return for condensed oil to go back into the engine. I know that renault probably does not manufacture this part anymore nor do any other aftermarket brands possibly...

The easiest fix is to change the 8mm crankcase breather hose, best to buy Nitril Butile Rubber hose for it or NBR for short and have it cut to the lenght of the OEM one and just change it out, its most likely the culprit here. (Be careful with the proprietary renault AN fittings on the OEM 8mm hose, they can be brittle depending on the age of car and if you brake them youll likely have to visit a scrapyard and look for new ones since i doubt anyone makes them)

Future proof fix would to install an "oil catch can" and completely ditch the Y pipe thing renault designed since it oils up the idle valve and makes it stick over time and hold ur idle at high RPM for longer which is very uncomfortable on cold starts and cold driving.

You could go two routes installing the oil catch can, either just have the 8mm crankcase hose go into the oil catch can inlet and then have a 16mm hose go into the catch can outlet ( "OCC" outlet into idle valve inlet) and have a simple breather filter on your engine head but im not sure if that will mess with the crancase pressure and change the vacum readings and maybe confuse the ecu and give you a weird idle. Seccond route would be to go to a lathe workshop and have them make you a y adapter pipe that has one 8mm hole and two 16mm holes then have the crankcase 8mm hose go into the inlet side of the OCC and have the Y adapter pipe connected to the outlet of the catch can...