New market down as overall number of vehicles coming into country falls.

Corolla Cross top model in September, BYD and Tesla climb up charts.

Aqua on top as five best-selling models unchanged from previous month.

New and used commercial sectors record year-on-year increases.

New monthly stats show total of registered dealers up by 15.

Year-on-year gain but number of new and used vehicles down from big July.

Nissan Leaf and Toyota Yaris make substantial gains in latest sales statistics.

Sales dip for new commercials but used market up 28.4 per cent year-on-year.