If there is a minor leak in the lines due to bumps, it is possible that the cooling may not work upon arrival. This is a normal physical loss. The cost of vacuuming, pressure testing, and recharging refrigerant at a local auto repair shop is low and is the buyer's responsibility.

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.