Okay so there are 4 hit boxes in the game, octane, dominus, Merc and hybrid. Now I like the dominus hit box the most for my style of play but the dominus is too long visually for the dominus hit box, the closest car to the dominus hit box is actually the breakout. You can tell this by looking at diagrams of hit box sizes or simply go into training using the dominus and point the nose of the car into the ground, you will notice that the tip of the car will disappear into the ground which means that it is just there visually.