The Audi Double Diamond four-wheel drive is now the Zhanlong four-wheel drive. If you want to build a high-end car, start with the chassis. You can use the original No. 19 narrow chassis, or you can buy its upgraded version, which is lightweight Quantify narrow chassis. Buy 6mm dustproof bearings and use them on the axles. Buy a 1.4mm reinforced four-wheel drive drive shaft. Hollow hexagonal shaft (light weight, strong, long or short). The most expensive kind has a dragon head and a phoenix tail, with side supplements. 2.5cm carburized screw set. Super fiber gasket. 18mm wind and fire guide wheels. 17mm wind and fire guide wheel (with bearing). High-speed gear (it depends on what kind of motor you have, there are 2.2:1, 31:1, etc.). Ultra-light wheels with integrated tires. High temperature resistant motor base (usually transparent). Silver plated guide. Then there’s the motor. If you don’t know how to wind a motor yourself, just buy a ready-made one. There are Viper motors, shock motors, etc. If you can wind it yourself, buy a super cool motor casing, rotor, 0.51 mm copper wire (can be used to wind a two-wire motor), motor back cover, and brushes. Finally, you need to buy special lubricants, bearing oil, and 2000 mAh or 1600 mAh double diamond Zhanlong batteries (note that 2000 mAh is 1.2 volts, two is 2.4 volts, and some motors can only use 3 volts , so you need to choose 1600 mA at this time). These can be combined into a high-end four-wheel-drive vehicle that can be taken to competitions. It will cost about 300 yuan. If you are a junior player, there is no need to buy so much!