Turbo the Clio mate, it'd be wicked!
As much as everyone can say, 'It'd only a Clio, why bother' it's YOUR Clio and for all it's flaws it makes up for it by sticking a smile on yoru face. Let alone one that could surprise most average Subaru/Evo/BMW drivers.
Put it this way, when I had my first 172 a Corsa pulled up alongside me. It had a loud exhaust and unpainted bumpers, I just assumed it was a 1.2 with a big exhaust. Pulled off at the lights, put my foot down and had my brand new shiny 172 annihilated by what turned out to be a 250bhp 2.0 GSI engined Corsa with throttle bodies. To me that's kinda cool and a turbo charged Clio 172 has the same appeal.
Lets face it you could always argue 'Yes but you could get this car and that' for X amount of money. Brand new RS Twingo or E46 M3 for example but it's not all about getting the most for your money, it's about having a car that makes you grin from ear to ear!