Normal. It is normal for users to replace the rear axle with Mercedes-Benz smart. Mercedes-Benz smart has lengthened the body length and wheelbase by 300mm and is expected to be equipped with a hybrid system. Smart's front and rear wheels are different in size. Mercedes-Benz smart generally means smart. The global joint venture company of smart brand is now jointly owned by Mercedes-Benz and Geely Automobile Group, and is committed to building smart into the world's leading high-end electric smart car brand. Since its birth, smart has always led the innovative practice of urban travel and embraced the development and transformation of electrification and intelligence in the automobile industry.