The serious racing world would assure you that it is a science and very complex one at that. For instance unless you know all the tyre stiffnesses, frequencies and slip angle progression, it is hard to model the car's behaviour correctly. But in the real world of saloons, which do their best to disobey most of the rules of physics, the best thing is to go to whoever is known to be most successful. I am a new comer to the Clio world, but not to motorsoort, and would reckon that the top Clio Challenge cars, or or instance in my part of the world there is a very quick Clio Williams doing some hill climbs, would give you a good guide. There are some basic rules, such as make sure that the geometry is set up correctly and if you are using coil overs that the car is corner weighted (with the arbs disconnected) which could save a lot of money. Also if using custom dampers get them tested annually.
