The C8 came from factory with 11 liters of transmission fluid. When I got the car I added the 2 extra liters that was recommended although I never tracked the car. While doing the drain and fill I removed 10 liters of fluid. As was mentioned there is still 2 liters of fluid in the DCT that can't be removed. That means I am missing 1 liter of fluid that I believe was drained out by a technician at GM when I took the car in to get the DCT canister filter replaced last year. They never performed the service (as they said they needed to keep the car overnight) but the technician spent 2 hours in the back with the car on the hoist. He wasn't qualified enough to perform the transmission service (the head technician was on vacation). Would you guys suggest that I put 1 more liter in?