I was just thinking, assuming that all iterations of the exhaust blown diffuser (including the ones being tried this season) are banned. Could they start pointing the exhaust so that a part of the hot gases go directly into the airbox of a following car when it is at a particular distance behind?
This would not only reduce the efficiency of that engine that has now to take in air at higher temp.but also increase wear and reduce life coz of the dirty air going in. would make overtaking, or even following much more difficult.