I want to buy a car and need logistics. If I don't understand logistics, can I unpack the car or something, just to see what's wrong with the car, that's all.

Yes, large items are usually unpacked by themselves in logistics. If there are losses caused by transportation, they demand compensation and refuse to sign. If the logistics is more specific and delivered to the door, the first thing to do is to open the box and inspect the goods. Generally, they will urge you to sign, and then sign after inspection.