A Mat Rempit is a Malaysian term for "an individual who participates in illegal street racing", usually involving underbone motorcycles (colloquially known as Kapcai) or scooters. Not all Mat Rempits are involved in street racing; some of them perform crazy stunts for fun, such as the wheelie, superman (lying flat on the seat), wikang, and scorpion (standing on the seat with one leg during a wheelie).
Mat Rempits usually travel in groups and race in bustling city centres on weekend nights. In recent times, Mat Rempits have been linked to gangsterism, gang robbery, street fighting, assault, vandalism, theft and bullying. Most motorcycles used by the Mat Rempits do not meet standard specifications, or have been modified extensively for greater speed, or just to make the exhaust noisier.
Additionally, some Mat Rempits do not have valid motorcycle licenses, do not pay road taxes, and ride stolen motorcycles. A growing number of housing estates have also been turned into racing tracks. It is estimated that there are about 200,000 Mat Rempits in Malaysia.
In some other countries, the term Mat Rempit is also used, but more to refer to one as a motorcycle lover or rider (Mat Motor), as opposed to an illegal motorcycle racer. Sometime the terms of Mat Rempit misused to refer any individual who rides an underbone motorcycle. Related to this is the Mat Konvoi, which claim to be the non-racing version of Mat Rempit.
cilok dari http://en.wikipedia.org/wiki/Mat_Rempit