Is that the peer group also are the main causes for this social problem?

Absolutely yes. It is because, most of the 'mat rempit' are still in the teenagers life. Well, it is normal for the teenagers who are really excited to try to do the new things. Same goes to the teenagers who are involved in this illegal racing which is very challenging to them. So, the peer group also are the most reason for this social problem. It is because, most of the teenagers are too easy to get influenced by this group. The main reason for this is because they are in the same ages and they have a lot of similar interests. Futhermore, if they do not do the same thing with their peer group, they will have a low self-esteem when they are in that group. They are also might be consider as an out-dated person.