For when that warranty runs out or if you don't care about that, one of the biggest things you could do is tune your car. The amount of information that the V2 shows on the screen that the factory 11th-gen Civic SI doesn't tell you is very helpful to the life of the vehicle. The TSP tune is also quality had it for around 20k miles now and two oil reports showed the wear metal within what the engine would normally do so so far for reliability its just like factory.
Had the catch can for a few months and gone through 2 oil changes since, and every time I've gone to clean it out, it's caught a good amount of oil. Would recommend it since that oil would've just gone on the valves if it wasn't getting caught, definitely gonna preserve power and engine life. The install was as simple as it gets, just two hoses and a few bolts, and it's on like it's factory.
Fits great, no CEL, and high quality welds. The first startup after install had me laughing with glee. It has a much deeper sound than the stock downpipe.
There was about a 300 mile break-in period for the chemical smells to go away.
Super easy install, engine seems to hover around 188 degrees. Installed at same time as an intercooler & charge pipe kit.
Coolant dump is annoying, but don't think there's any way around that.