I just picked up an STS. 2005. So far so good. Great car. I'm looking to add some after market upgrades. I want to start under the hood with a basic intake system. Any thoughts on a brand or website to buy from? Thanks for the help.
If you certain that you want an aftermarket CAI, then I would go with D3's on ebay there cheaper than K&N and they are the same design. People have said that the volant intake needs some modification to fit since it was orignially made for the SRX.
The volant can be fabricated to fit well if you are moderately handy with a hacksaw, grease pencil, and ruler. You shouldn't have to be at the price, but I still like mine plenty. It takes air not only from the fender well like the stock intake, but also the front grille and the box itself is much larger. I think it improves throttle response and air flow. As dkozlowski says, the major factor here is the sound, may be a mpg, but you won't get it, you'll rev it more.