Hi Chris,
As you know from my post in the topic about the 7876R a while ago I have the Genesis 5 Channel in my Megane which is soon to be transplanted into my 172 when I get it in June/July time. I would say it is a great amp for running a whole system. It has performed brilliantly over a wide range of music in the 3 years I have had it. Never had any electrical problems with it either. Looks great on show as well, with the polished brass and silver finish. It also has 2 sub outputs so you can run effectively a 6 Channel system.
The only thing I would say is that it is not the most powerful amp in the world. If you want pure loudness and heavy bass then it is probably not the one to go for, but for all round sound quality Genesis are top notch. If you want loudness then get one of their 4-Channels for the speakers and a Monoblock for the sub (but I think the Monoblock is about £1000 !!! Bit more than £450 !).
I would let you listen to mine if you are around Essex but I have just taken it out of my car as it is going into a bodyshop for a repair to the rear wing that someone crashed into.
BTW How were you thinking of installing it in the Clio as it is quite long ?
Hope this helps,
Cheers,
Carl