Insurance grouping is a bunch of arse, mine was rated at 15 but is cheaper to insure than with another company who rate it at 12 (as the book says) so i wouldnt go to much by what group its in...
for example if you smash up a RSturbo its going to be alot cheaper to rectify then smashing your renault, thats what bothers the insurance company, parts cost basically.
... and the fact you could hit a zonda for example in your clio, that upsets them aswell.