Might be different doen there Cubes, I have heard of Stock Evo VIII's being booked for non-standard FMIC...
I am a fan of using the standard route, and thus avoiding the cut and shut method that so many seem to use...
To me an exhaust that is too loud or a car too low is bodgy, its not hard to modify a car FOR THE ROAD and still have it legal...
I have a modified car and am yet to get a defect, touch wood, why, cause I have a reputable workshop work on it, and I check as much as I can first. There is obvious things that they will taget, and you have listed them, a bit of common sense comes to mind if you are going to drive on the street and frequent certain locations...
So what your saying is the workshops should be fined and not the people that let them install the crap...please