
A self-built car must pass the national design finalization inspection and production finalization inspection, be included in the national motor vehicle sales catalog, and complete the licensing procedures to obtain a driving license before it can be driven on the road. Below is relevant information about cars: 1. Overview: According to the latest national standard in China, 'Terms and Definitions of Types of Automobiles and Trailers' (GB/T-3730-1-2001), a car is defined as follows: A vehicle powered by a motor, with four or more wheels, not running on rails, mainly used for carrying passengers and/or goods; towing vehicles carrying passengers and/or goods. 2. Classification: Passenger cars: Passenger cars are primarily designed and technically characterized for carrying passengers and their personal belongings and/or temporary items, including the driver's seat, with no more than nine seats in total. Passenger cars are divided into the following 11 types. Mainly including: standard passenger cars, convertible passenger cars, luxury passenger cars, compact passenger cars, roadsters, hatchback passenger cars, station wagons, multi-purpose passenger cars, forward control passenger cars, off-road passenger cars, and special-purpose passenger cars; Commercial vehicles: Commercial vehicles are designed and technically characterized for transporting passengers and goods and can tow trailers, but passenger cars are not included. Mainly including: buses, semi-trailer tractors, and trucks.

Building a car by yourself and getting it road-legal is actually quite complex. I've seen many examples from DIY car enthusiasts. First, you need to ensure the vehicle meets safety standards, which requires comprehensive testing by professional institutions, such as mandatory indicators like braking distance and headlight brightness. Then, there's the environmental aspect to handle—emission standards are strictly enforced nowadays, so your self-assembled engine must pass the inspection line. Material preparation is also crucial; you'll need to gather invoices for all purchased car parts and complete vehicle design blueprints. Finally, take these documents along with the test reports to the DMV for registration, where they'll conduct on-site verification of details like the chassis number and engine number. Even if everything goes smoothly, the entire process can take up to two months, with costs mainly concentrated in testing and paperwork. I genuinely recommend understanding all these requirements thoroughly before starting your car-building project.

To make a homemade car legally roadworthy, safety is absolutely the top priority. First, the vehicle's body structure must meet strength standards, and the steering and braking systems must be reliable—all of which need to pass inspection at a professional testing facility. The lighting and signaling devices must also comply with traffic regulations, with hazard lights and brake lights being essential. Emission standards are becoming increasingly strict, so it's advisable to install an exhaust treatment system that meets the China VI standard. The entire approval process tests one's patience, requiring multiple trips between the testing station, environmental protection department, and vehicle management office. Many people fail due to exceeding the modification limit—remember, if over 30% of the vehicle's components are homemade, it may be classified as an assembled vehicle.

I built a small off-road vehicle myself and would like to share some practical tips. Safety inspections are absolutely essential – I recommend conducting dynamic tests like emergency lane changes and hill parking. Prepare key materials in advance: keep purchase receipts for every component, and remember to engrave identification codes on homemade frames. During inspection, the DMV will check measurements like wheelbase and track width, so it's advisable to reference production vehicle specifications during construction. Opting for mass-produced engine models makes future maintenance easier, and modifying the exhaust pipe can significantly reduce the risk of failing emissions tests. Don't forget to purchase compulsory traffic insurance before registration – this is non-negotiable. The majority of expenses will be spent on testing and certification processes.


