No, this is a serious customs violation. Complete vehicles (HS Code 8703) and auto parts (HS Code 8708, etc.) are subject to completely different import tax rates. Combining them on one invoice could lead to the invoice being returned by customs and may expose you to tax fraud accusations at the destination port.

We will directly check the registration certificate (the big green book) and count the number of changes.

Yes, but this falls under EXW (Ex Works) terms. In this case, the seller's risk transfers at the moment the goods are ready at the warehouse. Any subsequent domestic trucking accidents, customs inspections at the port, or issues with obtaining export licenses will be fully borne by your designated freight forwarder.