BMW Roof Rack Base Support System 3 Series Sedan & Coupe (1999-2005) Genuine BMW Accessory Modular Roof Rack System. Easily integrated with factory roof features, no drilling is required High tensile aluminum tubing offers a support system that is remarkably strong and corrosion-resistant. Complete with security coded bolts. Compatible with a wide range of BMW accessory attachments from cargo boxes to bicycle racks Compatible with a wide range of BMW accessory attachments from cargo boxes to bicycle racks