Chrysler Group LLC said it achieved a 27-percent domestic sales increase in September, the 18th-consecutive month of year-over-year sales gains. \"Irrespective of the economy, strong products equal strong sales, and with our retail sales up a whopping 50 percent, that is exactly what we have,\" Reid Bigland, head of U.S. sales at the company, was quoted by the Detroit News as saying on Monday. \"September was also our eighteenth consecutive month of year-over-year sales growth, and we have now gained more retail market share than anyone else in the country. There is no double dip downturn going on around here.\" Bigland added. The Auburn Hills, Michigan-based automaker sold 127,334 cars and trucks last month, up 27 percent from 100,077 units in sold in September 2010. However, sales declined 2.1 percent from the month of August 2011. The Ram Truck brand led the charge, posting a 42 percent increase in sales over September 2010.