Here are the stats for the Ion redline. It has 205 Hp (crank) and as you can see from their won advertisement on the page, a claimed 0-60 of 6.2
Mod for mod, (i.e intake for intake, exhaust for each, etc.) The redline is already behind in horsepower and torque. To help the original poster answer his question, race him and find out. But the Ion is already behind by 25 horses and 35 lb.s of torque if the guy who started the thread owns the 06 WRX. I never said the 06 is almighty, maybe others do, but I will simply reflect what Subaru built it with: 230 hp (crank, and 235 torque). SO 1) the Ion is already behind.
2) a mod like exhaust or intake done on both, will not help the Ion overcome the hp and torque it is behind, as both cars are similar in weight.
Assuming the Kdub has the manual, he would win in 0-60, WRX scores 0-60 in 5.49 and 1/4 mile in 14.11) You can find that here:
I looked into the Wrx and its competitors long and hard before I bought my 06 WRX, so I am familar with its stats, are you?
P.S. Did you see the Superman movie? It was bad. Superman with a kid? At least Batman is cool though.
Don't hate on others, you should simply follow your own advise next time and do or post the research yourself.