Welcome aboard!
One thing to keep an eye out for is the passenger side motor mount. At your mileage, it may break and spill a yellowish colored fluid onto you engine bay. It’s an easy item to replace and/or upgrade.
As for mods:
Look at Mazda3Revolution's wheel and tire picture thread. It'll show you a ton of combinations of suspension and wheel sizes. Eibach springs will give subtle drop and, when paired with Koni Str.t (aka Koni Orange) it's a comfortable ride. If coils are an option for you, check out Corksports, James Barone Racing, or some from BC Racing.
Some lowering springs, shocks and struts, and a rear sway bar will improve the handling and give it a less floaty feel. If you go lower, you may need rear camber arms to adjust the wheels back to spec. Some people haven't needed them, some have. But you might as well since you'll be taking the car apart for the springs, shocks and struts. I put in stainless steel brake lines on my 12 MZ3 SA and EBC greens that made the braking feel a lot better. The greens created a lot of brake dust, so I should have gone with EBC reds like on my Speed. Reds are less dusty and stop even better.
Check out
Corksport and
James Barone Racing for parts.
Don't bother with an intake and exhaust, unless you want you car to be louder. Neither will make the car go significantly faster.
Don't waste your time with Plastidip. It'll eventually end up looking cheap and terrible.
SPEND!!!
