KK guys, the clio and the C2 are poles appart, different classes of cars. I had a C2 GT (110bhp manual) before I got my 172.
The C2 handles well, stops well, parks easily and costs nads all to run and insure. Even the VTS is half the insurance of the 172.
For the plus side, the C2 is cheap to run, comfortable and better driving position by miles than the 172. Hardly any rear space in the C2 though, but a great boot design.
The 172 is more cramped in the front. It is quicker, handles better, costs ££££ a lot more to run and insure and for 5-6k you will be getting an older model out of warranty which is most likely going to need a few things doing, unless you get a real goodun.
The quality of the build imo is better on the C2 although it feels more plasticy, it rattles less. The C2 vts, is not all that diff from the GT, but is a fair bit quicker, apart from that they are essentially the same. The C2 VTS doesnt tune up well either, unlike its Saxo VTS predecessor.
Reliability on both the C2 and the Clio is poor. My 172 had more warranty work done than the C2 and from being a member of both car clubs respectively, both have their common issues and faults that cropped up again and again on the forums. Most of the ones I suffered from were niggly faults, though by the time I was trading my 172 on with circa 30k on the clock it needed some fairly expensive mechanical things doing.
Best thing is take both out for a drive. You may also like to consider the Corsa 1.8 Sri which is a bit of a half way house between the 2 although I would put it closer to the 172 than the C2 VTS. Again a goodun can be picked up for 6k (2-3 years old low mileage)
The 172/182 are proper hot hatches and have the running costs associated with them.
The C2 VTS is excellent at what it does which is provide a cheap and cheap to run warm hatch (not a patch on the saxo vts for performance though)
The Fiesta ST although more expensive has pretty much stolen the C2 VTS thunder in that segment of the cheap quick/warm/nippy hatch market and I guess that is why not many are sold when you can buy a new ST cheaper than a new VTS considering the finance options and deals Ford offer on them compared to Citroens, 'we like to bend you over APRs'.