When I first got the 335 (2011) there was a guy that was pushing all the limits with performance mods and trying all the new parts, etc. I followed his journey all the way through aftermarket turbos and I think he was one of the first to go single turbo, that I was aware of. A short time later he disappeared. Several months later, when he returned, he made a long post, reflecting on his journey and his observations of the process. My interpretation of his summary was that the car was designed to operate within a "performance envelope" where everything worked together and was relatively reliable. Once he got past the FBO phase, and upgraded the turbos, it started a cascade of problems (coils, injectors, pumps, engine, transmission, axles, etc.) that ravaged the reliability drove the cost of operation out of sight. His recommendation was be satisfied with FBO, where the car was very fast and still reliable enough to be a daily driver. Not go to upgraded turbos unless you were willing to relegate the car to toy/hobby status where it was not relied upon for transportation and you had a large budget to keep it going.
Each time I see someone make the jump to single turbo, followed shortly by them parting out the car and selling it, just to move to another platform, it reinforces his observations of a few years ago.
