Well i guess its just like drugs..could be one man's food and poison to the other...altho the show did enhance its credibility with on-the-spot dyno...but i do feel that probably they are doing it in isolation...car mod is always about modifying a few things to increase performance, that's why the Jap came out with stage 1, 2 etc..for every modification done to the intake, u may need to mod the waste that comes out such as to relieve backpressure via exhaust, and next u need to mod throttle. More intense mod will be supercharged and turbocharge, but u need to mod fuel-rail, BOV, injector..etc...etc.. then u need to do something about the suspension, the brake...otherwise the car would b undrivable.....just air filter alone probably there's slight improvement - maybe butt dyno can feel..who knows...

I think all perspective being taken into consideration, it boils down to car owner what sort of mod they have in mind - no necessary everyone will go for hp/torque...some may want only top-end gain...etc etc...some tuners wanted to improve performance but prefer N/A...as such tuning house such as HKS..Amuse...sometimes offer basic performance tune - which cover only -intake, exhaust, bodykit for downforce..and maybe add in carbon fiber bonnet for weight reduction - the figures quoted can range from 10 - 15% increase in HP - but whether its wheel-horse-power or otherwise is not release...so most assume if theres gain its good enough..but sometimes low-end torque increase - top-end suffer...its catch 22 - you gain some but also lose some...