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.

Welding Sparks

Welding Sparks deals X damage to target creature, where X is 3 plus the number of artifacts you control.

Fumigate

Destroy all creatures. You gain 1 life for each creature destroyed this way.

Kari Zev's Expertise

Gain control of target creature or Vehicle until end of turn. Untap it. It gains haste until end of turn.
You may cast a spell with mana value 2 or less from your hand without paying its mana cost.

Heart of Kiran

Flying, vigilance
Crew 3 (Tap any number of creatures you control with total power 3 or more: This Vehicle becomes an artifact creature until end of turn.)
You may remove a loyalty counter from a planeswalker you control rather than pay Heart of Kiran's crew cost.

Depala, Pilot Exemplar

Other Dwarves you control get +1/+1.
Each Vehicle you control gets +1/+1 as long as it's a creature.
Whenever Depala, Pilot Exemplar becomes tapped, you may pay {X}. If you do, reveal the top X cards of your library, put all Dwarf and Vehicle cards from among them into your hand, then put the rest on the bottom of your library in a random order.

Plains

Veteran Motorist

When Veteran Motorist enters, scry 2.
Whenever Veteran Motorist crews a Vehicle, that Vehicle gets +1/+1 until end of turn.

Aether Chaser

First strike
When Aether Chaser enters, you get {E}{E} (two energy counters).
Whenever Aether Chaser attacks, you may pay {E}{E}. If you do, create a 1/1 colorless Servo artifact creature token.

Thopter Arrest

When Thopter Arrest enters, exile target artifact or creature an opponent controls until Thopter Arrest leaves the battlefield.

Untethered Express

Trample
Whenever Untethered Express attacks, put a +1/+1 counter on it.
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.)

Mountain

Caught in the Brights

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

Inspiring Vantage

Inspiring Vantage enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {W}.

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.)

Pia Nalaar

When Pia Nalaar enters, create a 1/1 colorless Thopter artifact creature token with flying.
{1}{R}: Target artifact creature gets +1/+0 until end of turn.
{1}, Sacrifice an artifact: Target creature can't block this turn.

Reckless Racer

First strike
Whenever Reckless Racer becomes tapped, you may discard a card. If you do, draw a card.

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.)

Chandra, Torch of Defiance

+1: Exile the top card of your library. You may cast that card. If you don't, Chandra, Torch of Defiance deals 2 damage to each opponent.
+1: Add {R}{R}.
−3: Chandra, Torch of Defiance deals 4 damage to target creature.
−7: You get an emblem with "Whenever you cast a spell, this emblem deals 5 damage to any target."

Gearshift Ace

First strike
Whenever Gearshift Ace crews a Vehicle, that Vehicle gains first strike until end of turn.

Renegade Wheelsmith

Whenever Renegade Wheelsmith becomes tapped, target creature can't block this turn.

Aethersphere Harvester

Flying
When Aethersphere Harvester enters, you get {E}{E} (two energy counters).
Pay {E}: Aethersphere Harvester gains lifelink until end of turn.
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.)

Concealed Courtyard

Concealed Courtyard enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {B}.

Toolcraft Exemplar

At the beginning of combat on your turn, if you control an artifact, Toolcraft Exemplar gets +2/+1 until end of turn. If you control three or more artifacts, it also gains first strike until end of turn.

Scrapheap Scrounger

Scrapheap Scrounger can't block.
{1}{B}, Exile another creature card from your graveyard: Return Scrapheap Scrounger from your graveyard to the battlefield.