If Renault spent that much then is that why they use it on 1.4, 1.6 and all the various versions of na 2.0 in production?
It can be improved on, but imo itg panel is a waste of time, and yes ive had one.
the aftermarket panel air filters will indeed offer your engine better breathing but at the cost of poorer filtration, which in the long term will affect your engine cylinders, walls, pistons and piston rings
unfortunately the most damaging particles are the smallest ones - the very fine dust - which is not stopped by a "performance air filter"
if you plan to keep your car longer than 3 years I wouldn't advise changing from the OEM paper filter, which has the best filtration properties
Two words.... Mass Production
I agree it can be improved on, i suppose i should have worded my post better to say i prefer enclosed systems (the OEM airbox being one) rather than the flashy kits that claim this-that-and the other.
And id rather keep the standard airbox unless i saw substantial proof and scientific evidence that the expenditure on a different intake system would be making a reasonable improvement.
With the other part of your post I agree 100%, but the Clio V6 Ph2 airbox has a positive effect on the bhp & torque - first hand experience.
Will post results as soon as I get my car on the dyno. Maybe won't be 100% precise because I had my flywheel lightened, and then I got the airbox, but you get an idea.
And just because of the mass production and the "economy of scale" it's easier (read: CHEAPER) for the manufacturers to use as much of the same parts as possible - and that can leave room for improvement.
While the aftermarket manufacturers (by that I mean tuning companies such as K&N, KTR,...) don't need to look after the ecological standards (most of them), and they charge their products well so the production cost is not such an issue.