Model made in blender by me.
This mod adds a new car prototype called SA-mauler that has a machinegun flamethrower, optional sized equippment grid and multiple options including:
HP amount and Tree Immune.
This car heals itself when colliding with biter nests, worms and trees, you can toggle more including these in mod settings.
K2 Equipment Compatable and IR3 Fuels Compatable.

Settings I recommend are:
If heal with biters is on then: Tree Immune Off, Healing at 0.25 for a challenge 0.35 for getting accustomed to it.
If heal with biters is off then: Tree Immune On, Healing at 0.35 for a challenge 0.45 for getting accustomed to it.

For reference the car has rocket fuel here