A car crashed into a Dorchester fabric store shortly after 4 p.m. yesterday, Boston police said. The driver of the car sustained injuries described as not life-threatening and was transported to Carney Hospital in Dorchester, police said. The business, Sewfisticated Discount Fabrics in Lambert’s Plaza at 735 Morrissey Blvd., was closed for the rest of the day because of safety concerns. A police spokesman said the cause of the accident is under investigation.