It depends on the specific repair and the person's level of knowledge and experience with car repair. Some minor repairs, such as replacing a tire or changing the oil, can be done safely by a person with basic mechanical skills. However, more complex repairs, such as fixing the transmission or brake system, can be dangerous and should only be performed by a professional mechanic with proper training and equipment. It's always important to follow the manufacturer's instructions and take appropriate safety precautions when working on a car.