They are not the only parallel twin around. They been around for decades, but in today world, prob all around Australia. There is that very particular exhaust note……changing up at close to full revs then you look around (if you are on your pushbike or walking around) and its 9 times out of 10…..a Ninja rider with a L plate. Air cooled Harleys are easy, but the VRod has another very distinctive note. the M109 has its own note. R1 has its own note. Does that make me an enthusiast, if I can sniff out a mbike model before I see it?