In short, at first glance, the Greenwood Special is closer to a car than a sidecar.
Owen Greenwood, and especially his machine, will be very contested by other competitors, and for the simple reason that he won all the races! Some will even question the usefulness of the passenger as the Special Greenwood was very stable.
Moreover, his opponents will soon show their displeasure by asking purely and simply the banishment from British circuits of the Greenwood Special!
However, Owen Greenwood did not build his machine without thinking in depth and had examined in detail the racing rules. It also stated, among other things, that if two rear wheels were spaced less than 8cm, they were regarded only as a single wheel. You can imagine that the two rear wheels of the Greenwood Special were spaced less than 8 cm ...
The story around this machine is still quite unclear, but it seems that after having won quite a lot of races, the Greenwood Special was finally banished from the circuits anyway...