Basic rules for power upgrades are:
If you want more power:
1. You have to have model series most powerful version brakes, suspension etc. Clio 197 is most powerful of clio 3 series so no problem with that. So if you have 1.6 clio, you have to first change 197 suspension and brakes etc...
2. You can put 20% more power. You have to have dynograph from goverment approved test center, usually they seal wastegate etc and mark boost pressure in car documents. If you put more boost, it is illegal car.
3. If you for example turbo/supercharge n/a engine, emissions are different and they want really expensive emission laboratory test, price something like 2000£ no matter pass or fail..
I am so sad because for example in USA if you have E46 330 , just bolt on supercharger and you have over 300horsepower and lot of torque. Here it is impossible. I would use 4000$ for supercharger kit no problem if it is legal..