1. Place a Hatchback. Place a vehicle with plenty of engine power like an Ifrit directly in front of the Hatchback.
2. Give the vehicles variable names (e.g. v_car, v_ifrit) and place a character to play as.
3. Start the mission.
4. In the debug console, enter:

rope1 = ropeCreate [v_ifrit,[0,-4.5,-1.3],v_car,[0.4,1.9,-1.1],6]; 
rope2 = ropeCreate [v_ifrit,[0,-4.5,-1.3],v_car,[-0.45,1.9,-1.1],6];
v_car setTowParent v_ifrit;

5. Get in the driver's seat of the Ifrit and attempt to drive away. Note that the Hatchback refuses to budge.
6. Optionally, experiment with setMass and disableBrakes on the Hatchback and note there is no appreciable difference.

You can repeat this test, replacing the Hatchback with another Ifrit or a Hatchback Sport, to demonstrate the problem is unique to the Hatchback.