British car sales sank in October for the seventh successive month on disappointing consumer demand, industry data showed on Monday. New car registrations sank 12.2 percent year-on-year to 158,192 vehicles last month, the Society of Motor Manufacturers and Traders said in a statement. The SMMT blamed the sharp drop on falling consumer confidence - and confusion surrounding the government's air quality plans. Under a change in UK tax rules that came into effect in April 2017, all new cars - except for those with zero carbon dioxide emissions - are now subject to an annual flat-rate charge.