If you plan on using the Liqui Moly injector cleaner, use it first, and then followup with ultrasonic injector cleaning, since liqui moly will break free long staying deposits from the fuel tank, fuel rails, and the last place that all will end up will be the injectors, given they get beyond the fuel filter. For the injectors, since they fire on such a precise manner, nothing will beat ultrasonic cleaning.
For the plugs, I am still wondering which ones to get for my car as well. I installed two spoke NGK ones, which I now believe are the replicas, since the fuel mileage has deteriorated excessively.
@hash4u , buddy how was your experience with these NGK platinum ones? Decent fuel average?