Right,
The Original clio cup race wheel - 2118 ET48.5
They then started using - 2118 ET38 sometimes the 2020 mag version but that cost to much to replace as said.
The 2118 ET43 is a high duty palmersport clio cup wheel, designed to take abuse from the general public on the palmersport driving days. It weights a lot more than the et38 version.
I have owned quite a few sets of 2118's over the last 4 years not one has been designed to be used with a centre cap. On the rears you can use the hub covers that can be found on lesser spec clios and painted a colour of your choice, i havent found anything for the fronts yet.
I wouldnt want a modified centre cap on my car because theres a chance it will fall out, the wheel wasnt designed for centre cap's so i wouldnt risk it. And i wouldnt glue them in either...