Interesting, that this form-factor was popularized by DIY builders. First one was dutch-built, sponsored by Red Bull after prototyping stage, to film Verstappen's full F1 lap (so semi-DIY, so to say), but then record was taken back and forth between two DIY builders — Ben Biggs in Australia and Luke Maximo and his father
Latest record by Ben Biggs was 626kph (389mph). Latest record by Luke Maximo was 655kph (408mph).