Since we aren't allowed to go supersonic unless in a corridor in the middle of nowhere above 40,000' in the US the best we can do at an airshow is the, "Sneak attack".
The main show is performed in front of the crowd while one of the wingman detaches and maneuvers around to behind the crowd line and just as the main performers are at the peak of what ever maneuver they are doing the wing man comes in from behind
usually in the 500 knot range with engines at idle to reduce anyone hearing the plane rapidly approaching then rams the turbines to full power about 1-2 seconds prior to crossing the crowd line at minimum altitude allowed. I think when I did it was 200' AGL.
Maybe a wee bit lower
Then snap on a 5.5 G turn to exit the line.
The sonic overpressure would usually would start a cacophony of car alarms in the parking lot as I was flying the loudest airplane in the world.
since the Concorde has been retired.
Throwing a sonic boom doesn't sound plausible but I would have to do the math and I lost my slide rule some where
Sparky
PS How can the Brits build both the most beautiful airplanes in the world as well as the ugliest?