In my experience there are idiots driving all brands . As the commodore is a very popular car and they sell a quite affordable performance version , it makes sense that the young blokes are attracted to them.
I'm sure they'll find something else to drive when the time comes .
I have to ask . Why do you drive at 5km under the limit ? I've often wondered why people do this as it is quite disrupting to the flow of traffic ( hoons not included ) .
As someone posted , a lot of new speedos are slow . Mine is 8 kph slow according to my gps.