Is the issue with direct injection engines as far as carbon build-up on the backs of valves a real issue or more hype? And, is a GDI engine with a turbo an even bigger concern? Going to need a new vehicle in the near future, so I've been reading about this issue. I tend to keep my vehicles for a long time and it seems like owners like me are those with the greatest risk of the costs associated with maintenance. Any firsthand experiences to share?