Technical problems with braking systems and weak demand in China saw third quarter profits fall by 84% on the year to €476 million ($512 million) at German carmaker BMW in results published on Wednesday. Reduced unit sales led to a fall in turnover to €32.4 billion, down 16% on the year. Costs caused by technical measures and a halt to deliveries resulting from problems with brakes provided by German supplier Continental hit profitability in BMW’s core business. The profit margin in the car unit before interest and taxes dived 7.5 percentage points to 2.3%, badly impacted by declining sales in…