AST 5200 Series Coilovers | 2012-2015 BMW M3/M4 (RIV-B2102SD)AST 5200 Series Coilovers 20122015 BMW M3 M4 5200 Series Coilovers Part #: RIV B2102SD Overview The AST 5200 Series Coilovers are a high performance suspension upgrade designed specifically for the 2012 2015 BMW M3 and M4 models. Engineered for enthusiasts who demand precise handling and exceptional control, these coilovers elevate your vehicle's driving experience whether on the street or the track. With their advanced adjustability features, you'll