Siege Modification

Enchant creature or Vehicle
As long as enchanted permanent is a Vehicle, it's a creature in addition to its other types.
Enchanted creature gets +3/+0 and has first strike.

Giant Ox

Giant Ox crews Vehicles using its toughness rather than its power.

Foundry Inspector

Artifact spells you cast cost {1} less to cast.

Mech Hangar

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Pilot or Vehicle spell.
{3}, {T}: Target Vehicle becomes an artifact creature until end of turn.

Hotshot Mechanic

Hotshot Mechanic crews Vehicles as though its power were 2 greater.

Fleetwheel Cruiser

Trample, haste
When Fleetwheel Cruiser enters, it becomes an artifact creature until end of turn.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Consulate Dreadnought

Crew 6 (Tap any number of creatures you control with total power 6 or more: This Vehicle becomes an artifact creature until end of turn.)

Imperial Recovery Unit

Whenever Imperial Recovery Unit attacks, return target creature or Vehicle card with mana value 2 or less from your graveyard to your hand.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Armed and Armored

Vehicles you control become artifact creatures until end of turn. Choose a Dwarf you control. Attach any number of Equipment you control to it.

Mountain

Scrapyard Salvo

Scrapyard Salvo deals damage to target player or planeswalker equal to the number of artifact cards in your graveyard.

Axgard Armory

Axgard Armory enters tapped.
{T}: Add {W}.
{1}{R}{R}{W}, {T}, Sacrifice Axgard Armory: Search your library for an Aura card and/or an Equipment card, reveal them, put them into your hand, then shuffle.

Caught in the Brights

Enchant creature
Enchanted creature can't attack or block.
When a Vehicle you control attacks, exile enchanted creature.

Aerial Modification

Enchant creature or Vehicle
As long as enchanted permanent is a Vehicle, it's a creature in addition to its other types.
Enchanted creature gets +2/+2 and has flying.

Pia's Revolution

Whenever a nontoken artifact is put into your graveyard from the battlefield, return that card to your hand unless target opponent has Pia's Revolution deal 3 damage to them.

Peacewalker Colossus

{1}{W}: Another target Vehicle you control becomes an artifact creature until end of turn.
Crew 4 (Tap any number of creatures you control with total power 4 or more: This Vehicle becomes an artifact creature until end of turn.)

One Last Job

Spree (Choose one or more additional costs.)
+ {2} — Return target creature card from your graveyard to the battlefield.
+ {1} — Return target Mount or Vehicle card from your graveyard to the battlefield.
+ {1} — Return target Aura or Equipment card from your graveyard to the battlefield attached to a creature you control.

Ovalchase Dragster

Trample, haste
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)