The issue with these cars are lack of maintenance. These cars have a issue with fuel mixing with oil and causing the engine failure. Also since it's a gdi carbon build up is a problem. With these cars you have to decarbon every 10k miles and change oil every 3,000 miles. They also have fuel pump issues and battery. I also believe they have a issue with injectors leaking and or dumping to much fuel. I also think I heard they had a upper ring issue but I can be mistaken.

So with this car maintenance is everything. You can't put it off or skip especially oil changes. 

To decarbon or induction cleaning is done by vaporizing or adding a liquid chemical spray into air stream after the mass air flow sensor. You usually hold rpms around 2500 to 3500 rpms and slowly add products. Depending on what you use it can take up to 20  minutes to finish spraying. You can introduce spray through vacuum line as long as it is after the maf sensor. Make sure you don't spray any sensors inside throttle body directly.  I included 2 videos that will help you have a better understanding.  Having the engine walnut blasted is the only real way to properly remove carbon  but cost quite a lot to have done. When using spray to remove  carbon I can take a 2 or 3 treatments especially if it hasn't been done before. You can use something like Seafoam upper engine cleaner, stp pro series valve cleaner, pro line liqui molly intake valve cleaner, bg 44k induction cleaner. This is just a couple of them there are a lot out there. I've used Seafoam upper valve and  stp professional and had great results. Your other option is getting a induction canister from Amazon and buying the chemicals. Unless you know exactly what your doing I would stay away from that method. It is very easy to introduce to much liquid and hydro lock it. Do not buy regular Seafoam and pour into vacuum line. If you do it wrong or add to much you can cause damage. When doing it make sure the car is at fully running temp and let it heat soak for a couple of hours for best results. Make sure you pay attention to the rpms. Even tho you have it set at 3000 once carbon is being removed your rpms will shoot up and they will have to be reset.