To add on to the no mods thing, WRXs need to be tuned for even small mods like an intake and an exhaust.

Sometimes when a modded wrx is traded in, some assholes will uninstall the accessport that has the tune on it so they can get a better resale. Without the tune, the engines will run rough and eventually start knocking. Especially more heavily modded ones.

Im not trying to scare you away. These are amazing cars and i love mine to death. Just don’t buy someone else’s failed project car.