Any car on the road will beifit from getting more air flow. Engines are basicly large air pumps. The more air getting in, the better the fuel mixiture. So your coworker is somebody that thinks your car is a POS and shouldn't be on the same road with his Honda Civic / Ford Mustang / or big time muscle car.
You COULD do what he said, but there's not really much of a point to that. The rubber acoordian piece is very restrictive and WILL take away any postive to the cone filter.
I run a WAI on the street and a CAI on the track. You can ask Mitch (Daytona) my car ran 1/2 second faster with the CAI over the WAI. Plus I run my CAI with the fender liner and fog light both out of the car.
The sound will change a little bit. You may notice it a lilttle bit when the weather gets colder. I personally don't like CAI's because I fear water suckage and road debis, this includes road salt in the winter time.
It's be beaten to death on here about which is better, CAI or WAI. WAI will give you a bit more torque over the CAI, and the CAI will give you a bit more HP.
Slicone Couplers, piping, and your set. Yes it will be a good upgrade for the car. Throw an exhaust on there later and you'll be set. The car's breathing better, it's got to emit better too