There arent any substantial power gainers that you can get for an auto. The trans just wont hold up under power. And 200-500 isnt really that much. You might be able to get a used header and muffler for that price. But an intake, header, and muffler arent going to do more than change the exhaust tone.
70 thats gas and a car wash....lol but no bolt ons add any noticeable power honestly and a tranny swap for a 8th gen dats gonna cost more den building a gsr motor
Dude an auto to manual swap is just out of the question. For cheaper than the price of your car, and an auto to manual swap, you could buy like an 06 or 07 Si. Do that instead.
Intakes sound good so they give the impression of more power. For $70 dollars, an intake would probably give you the most gains, however, for the money. Plus they look good! I like short ram intakes, but that's just me.
I agree with Nike, his WHOLE post. You dont know what the f**k you want. You go from modding your car, to a transmission swap, to trading it for a car that is 14 years older. Figure out what the f**k you want, and THEN act on it.