sidecars that are outside of the technical rules are permitted to compete in races but their results, points or finishes are not recorded. An example is the Markus Bösiger/Jürg Egli team who would have finished third in the 1998 championship season. However, as they were using a configuration where Bösiger sat in an upright driving position no results were entered in the official records. Under FIM regulations, "rider" applies equally to the driver and the passenger on a sidecar. The driver is positioned kneeling in front of the engine with hands near the front wheel, while the passenger moves about the platform at the rear transferring their weight from left to right according to the corner and forward or back to gain traction for the front or rear. The passenger also helps the driver when it comes to drifting, and is also usually the first person to notice any engine problems since he is next to the engine while the driver is in front of it. The two must work together to be a successful team. Nowadays it is common to call the driver the "Pilot", while the passenger has several nicknames: the "Acrobat" used in North America which is no longer in use, and the now common term "Monkey" which originated from Australia. Occasionally the words "Co-Driver" or "Co-Pilot" are also used. Traditional sidecar racing remain popular in several countries, especially the United Kingdom, where it known as Formula Two Sidecars (600cc Engines). They are generally uses in true road racing events like the Isle of Man TT races. Despite their lower top speeds, these machines retain better manoeuvring capabilities. Modern racing Between 1981 and 2016 Superside machines were known as Formula One sidecars using a basic unchanged design. These modern high tech machines are only related to motorcycles by the classification of the engines they use. All chassis are purpose built and owe more to open wheel race car technology and the tires are wide and have a flat profile. They are sometimes known as "worms". The most successful sidecar racer in Superside has been Steve Webster, who has won four world championships and six world cup between 1987 and 2004. The most successful chassis is LCR, the Swiss sidecar maker, whose founder Louis Christen has won 35 championships between 1979 and 2016, with a variety of engines, originally Yamaha and Krauser two-strokes, more lately Suzuki four-strokes. The