Re: 147 Air induction.
Unless you're in 'boy-racer' loud thrashy noise mode, all you need to supply more than enough air is a K&N or BMC replacement element.
Depends what you want, but then that's always true... Personally i wouldn't be caught dead with an open cone in the engine bay beacuse of the hot air ingestion, so it's mod the standard system or fit a CDA such as a BMC or Viper.
I'd fit a replacement element and spend my money elsewhere where you'd see far more benefit (ECU remap for example).
Also, don't believe all the twaddle about oiled filters killing MAF's. This was a corporate rumor started by a rival company, and has circulated among motoring groups ever since. Absolutely, cetegorically, a correctly oiled filter will not shed oil. All filters supplied by BMC & K&N are correctly oiled. Believe the science not the gossip ang hype.