Registered trademarks for vehicle products in the Nice Classification of Trademarks are Group 1202 automobiles, trams, motorcycles and their parts in Class 12.

Tractors are in Class 12 Tow vehicle 1202, trailer 1202, and trailer (vehicle) 120056 (of the broken down vehicle) are all tractor trailers

As for the type of modified vehicle trademark registration you mentioned, it depends on your modified vehicle. For example, when modifying a vehicle for cargo transportation, you can choose: light truck 1202, delivery truck 120076, truck 120022, etc. For passenger vehicles, you can choose buses 120018, buses 120019, sports cars 120178, campers 120249, RVs 120249, etc. It also depends on the specific purpose of your modified car.