Got to say I do love the blue 197s, making me regret getting a white 200 after looking at some of your pics!
Just a question about the flat spot, have you checked your MAP sensor to see if its loose? Take a look at
this post. If it's loose it can cause a
vacuum leak, which apparently leads to a much more noticeable flat spot.
Mine was loose and I cable tied it to secure it and the car felt completely different, flat spot was a LOT less noticeable, maybe it's worth a shot on yours?
Let me know if it makes any difference to your flat spot .