First Step To Make M45 Stronger, but what about Faster?

[Xoxopromesa]

06 m45, decent looking car . V8 of course. nothings better than having custom works under the hood and surprising someone because the outside doesn't match the inside.
I guess what im really asking is what small tweaks can be done to increase speed without actually going all out on kits. (Althought do plan on buying in the future)
example. i know some types of filters may also use cold air in the engine, which can increase its power, or use intake tubes to draw more air into engine. performance air intakes allow the engine to burn fuel more efficiently to add more horsepower to your car. but then again that increases hp not really speed.

[Double E]

Google uprev

[EniGmA1987]

Cut out the cat's, put an R2C intake on it, and tune with UpRev.