I've got to add my favorites too.

Rob Dahms 4 rotor: https://www.youtube.com/watch?v=JOmDj9iPs5o

This 240z: https://youtu.be/9PAHenR3JgQ?t=10

Le mans hybrids that sound like world destroying alien spacecraft: https://youtube.com/shorts/HXD5Gao4F5k?feature=share and https://www.youtube.com/watch?v=FqyGJTioXnc