Armored Carriage

Carriage Front Armor. A 3' high iron wall wraps around the front bench of the carriage.  Provides 1/2 cover (+3 AC) to driver & shotgun rider for any ranged attacks.

Wheel Spikes.  Spikes installed on each wheel of the carriage. Any attacks on the wheels have disadvantage. The wheels themselves have 50 HP, once a wheel is broken the carriage rapidly comes to a halt. The wheel can be repaired on a DC 15 Slight of Hand check. (it is up the DM on how much HP the wheel recovers)

Trample. When the carriage runs someone over it makes an attack against them. See actions for (Trample) attack.

Electrical Conductivity. Though the carriage itself is immune to lightning creatures inside will be subjected to half the lightning damage the carriage takes.

Trample. Melee Weapon Attack: +5 to hit, reach 5 ft, Hit: 10 (4d4 + 4) bludgeoning damage. 

Batten the Hatches. An iron set of front and rear doors may be locked as an action. Cannot be unlocked from the outside. They may be pried open by a STR check DC 20.

Arrow Hatches. On the left, right, and back on the carriage there are hatches, they may be opened to allow an archer to shoot through them. They are to small to allow any creature larger than the size tiny through them. The size of the hatches are 1' wide and 6" inches tall. You may open or close them as a bonus action or regular action.