What about those ridiculous stretched tyres? Rear wheels with massive amounts of camber? Plenty of other unsafe stuff going on (just look on social media to see the amount of young drivers cutting suspension springs to lower their cars). Remapping if done correctly can actually improve emissions in certain cases, as they manufacturers use a “best case” map when they build the cars, ones that work for mass production. Correct mapping improves on that, as it is tuned specifically to the car. Obviously removing catalysts and DPF’s is a no go due to legislation, although there are options for using sport cats or high flow units.