The ever hardening interest rates has impacted the growth of domestic automobile sales in March with passenger car sales growing by just 2.89% while the motorcycles segment saw a dip of 3.5%.According to figures released by Society of Indian Automobile Manufacturers (SIAM), domestic passenger car sales stood at 1,14,195 units as against 1,10,978 units in the same month a year ago.The slow growth in March acted as a dampener on an otherwise good FY07, in which domestic passenger car sales grew by 22.01%, while motorcycles posted a healthy 12.79% upswing.While car market leader Maruti Udyog maintained a sales growth of 7.06% at 55,623 units in March this year as against 51,951 units in the same month last year, rival Hyundai Motor India saw a dip in its sales at 19,242 units as against 22,486 units last year, down 14.42%.Homegrown auto major Tata Motors posted a growth of 11.3% at 19,651 units as against 17,655 units in the same month a year ago.According to analysts the 'almost-flat' sales were partly because of the hardening interest rates, which has resulted in higher EMIs.They, however, pointed out that overall sales in March last year was high on account of the 8% excise duty cut announced on small cars thereby making the base higher for comparison.Motorcycle sales in the country declined 3.5%, mainly on account of two major manufacturers Bajaj Auto (BAL) and TVS Motor slipping up, even as market leader Hero Honda managed to post a growth of 6.02%.