Your all just generalising.
Yes their are goons and wanksters driving skylines but doesnt that go for other cars as well? Not only holdens, but their are people who drive recklessly in pulsars, excels, 323's...even bloody camry's n shyt.....Its not the CAR or the ethnicity, its the PERSON who sits behind the wheeel.
One thing i do agree to is AGE does make a big difference. As it is obvious that with age comes maturity and experience, so the older you are, the less likely you are to go around doing stupid things like high speed cornering, donuts etc. etc.
Just my 0.00000000000000002c