The blessed warrior fighting style gives you a couple of cantrips for paladin

Play a Tabaxi monk multiclassed with a level of wizard and get the mobile feat then cast tensers floating disc and tell your friends to get on then start running

I definitely think some of these ideas are fun, but I do want to highlight that my goal for this build was a character who drives a cart or uses a mount, not become the mount themselves. 

As another point, I think a fun choice for this build would also be to use a whip as your primary weapon. It is thematically fitting as a driver of a cart or carriage and has the added benefit of smites with reach if you go the paladin route. This would also allow you to drive around the battlefield making melee weapon attacks without necessarily provoking opportunity attacks. 

I had a similar idea on the Artificer side. but lets go through this one...

-Vehicle proficiencies 

-Able to be effective in combat while mounted (either with melee weapons or more likely ranged weapons/spells)

-Access to spells which can be used to buff any creatures you are mounted on or which are pulling your cart or what have you. 

For this I am going to assume; Land vehicles, 3 party members to transport (800 lbs ish), speed and evasion are required, and that we are in an urban environment. Level 1-5 

For vehicle proficiencies, I believe the easiest way to get them is via the Folk Hero or  Criminal Spy background. The criminal makes sense as you are a get-a-way driver. With this, we are going to buy a cart with the gold that comes with the background. 

We will then go artificer for three levels and go Battle smith. I explained in the linked post how the Steel Defender is more than capable to pull a cart. The medium size of the SD as a beast of burden would be a benefit gaining access to smaller spaces than a larger horse or mount with and without the cart.

With Magic Tinkering will I will install spotlights bullseye lanterns on the cart, and if the village town has a fire department or the like that uses bells, horns on their vehicles, I ll would replicate that sound as well, as a way to get people out of the way. 

Infusions I would pick Alchemist Jug, Bag of Holding,  HOMUNCULUS SERVANT, and ShiftWeave.  The Bag of Holding is for storing the loot and to reduce the weight that the cart carries, The Alchemist jug is for making bottles of Oil, Acid and Honey (sticky) that can be dropped by the HS (using my bonus action, and commanded by light signals (magic tinkering), that will be used to slow down the pursuers. Shift Weave will be used on the cart covering and will be changed as a means to disguises the cart ( are they chasing a red cart or a green one?)(If the shift weave cover is a DM no go, pick up instead SpellWright tattoo and Silent image.  If the cart looks like a poop cart and smells like a poop cart (magic tinkering) who is going to look closely at the poop cart?)

Main Spell that I would prepare: Land Strider onto the Steel Defender for 50ft movement speed. Web cut-off routes and pursuits. and Rope trick to make a hiding hole. 

Quote from Utsu_Yami >>

I had a similar idea on the Artificer side. but lets go through this one...

-Vehicle proficiencies 

-Able to be effective in combat while mounted (either with melee weapons or more likely ranged weapons/spells)

-Access to spells which can be used to buff any creatures you are mounted on or which are pulling your cart or what have you. 

 

For this I am going to assume; Land vehicles, 3 party members to transport (800 lbs ish), speed and evasion are required, and that we are in an urban environment. Level 1-5 

For vehicle proficiencies, I believe the easiest way to get them is via the Folk Hero or  Criminal Spy background. The criminal makes sense as you are a get-a-way driver. With this, we are going to buy a cart with the gold that comes with the background. 

We will then go artificer for three levels and go Battle smith. I explained in the linked post how the Steel Defender is more than capable to pull a cart. The medium size of the SD as a beast of burden would be a benefit gaining access to smaller spaces than a larger horse or mount with and without the cart.

With Magic Tinkering will I will install spotlights bullseye lanterns on the cart, and if the village town has a fire department or the like that uses bells, horns on their vehicles, I ll would replicate that sound as well, as a way to get people out of the way. 

Infusions I would pick Alchemist Jug, Bag of Holding,  HOMUNCULUS SERVANT, and ShiftWeave.  The Bag of Holding is for storing the loot and to reduce the weight that the cart carries, The Alchemist jug is for making bottles of Oil, Acid and Honey (sticky) that can be dropped by the HS (using my bonus action, and commanded by light signals (magic tinkering), that will be used to slow down the pursuers. Shift Weave will be used on the cart covering and will be changed as a means to disguises the cart ( are they chasing a red cart or a green one?)(If the shift weave cover is a DM no go, pick up instead SpellWright tattoo and Silent image.  If the cart looks like a poop cart and smells like a poop cart (magic tinkering) who is going to look closely at the poop cart?)

Main Spell that I would prepare: Land Strider onto the Steel Defender for 50ft movement speed. Web cut-off routes and pursuits. and Rope trick to make a hiding hole. 

 Love it. Another great option

Quote from Utsu_Yami >>

I had a similar idea on the Artificer side. but lets go through this one...

-Vehicle proficiencies 

-Able to be effective in combat while mounted (either with melee weapons or more likely ranged weapons/spells)

-Access to spells which can be used to buff any creatures you are mounted on or which are pulling your cart or what have you. 

 

Main Spell that I would prepare: Land Strider onto the Steel Defender for 50ft movement speed. Web cut-off routes and pursuits. and Rope trick to make a hiding hole. 

 Adding more Artificer spell suggestions: Pyrotechnics, for a smoke screen to get away, Disguise Self, in case you need to use it to infiltrate or escape, and Blink, in case the party screwed up and you need to avoid getting caught.

If you go Armorer, this is a good time for your Infiltrator armor for the speed and stealth improvements.  Again, it’s only going to help if things go sideways- which they probably will.

Quote from Kaboom979 >>

I definitely think some of these ideas are fun, but I do want to highlight that my goal for this build was a character who drives a cart or uses a mount, not become the mount themselves. 

 

As another point, I think a fun choice for this build would also be to use a whip as your primary weapon. It is thematically fitting as a driver of a cart or carriage and has the added benefit of smites with reach if you go the paladin route. This would also allow you to drive around the battlefield making melee weapon attacks without necessarily provoking opportunity attacks. 

 If you aren't the mount then how about you make your companions be the mount by pulling the cart, as you whip at them to make them to faster.

No mention of Druid yet, but I think it may be worth a look. The various summoning spells may get you your beast of burdon and you have the rest of the spell list for support.

Or... be the "driver" with circle of the moon. Lose out on some utility, but whoever is in/on the cart no longer has to hold the reins and could provide it instead.

Another idea is to cast tensers floating disc and ride away on a fast horse.

I'm starting something similar to this tomorrow night. I wanted something semi crazy or silly that works on a theme with other party members. Nobody really bit on the baby bjorn idea, even if I was the big guy. So I'm going for a cart pusher/puller, with the goal of other party members helping with the drive-by.

Going Orc for the Powerful Build to carry most likely more than a cart can hold. I loaded it down with loads of useless flavor stuff and he can still bench press this cart, or pull it up a cliff, etc. And five times that amount when pulling it. And thats with only a 16 Strength. The Orc's Aggressive trait lets them move towards the enemy as a bonus action. Bonus Action move to the enemy, Action to either Shove the enemy Prone, Dodge, Disengage, etc then use regular movement to move away from the enemy. Reflavoring him as a Half-Orge as an homage to a really old character I had back in the day.

Failed Merchant Background from Acquisitions Incorporated for the Vehicles(Land) proficiency. He's now an ex hot dog vendor who runs around the fight with his old hot dog cart.

Starting out Barbarian for the hit points, rage damage reduction ,advantage on Str checks, and aiming for Wolf Totem at Barbarian 3.

Rogue 1 for the Expertise in Athletics, much later taking that up to Scout for some Reaction movement.

Fighter 1 for a touch of self healing, Superior Weapon Technique Commanders Strike to get the Rogue another sneak attack in the round(she's probably flying at this point) Later on take the build up to Eldritch Knight to get Shield, Jump, Longstrider, etc (8 Int and looking like the only Arcane Caster in this group)

If I can convince a few party members to ride along in the cart and start prepping up some Readied Attack Actions?  Cool, might be able to drop most good sized enemies every turn while running around. Or maybe they just want to shoot ranged from the cart and appreciate being away from melee? Some cover from the cart? We'll see how it goes.

I kind of built this guy with the goal of having 2 or 3 party members in the cart. So it's up in the air at this point on how much the other characters are onboard with it. The build "plan" is more of a guideline at this point so I can adjust it depending on the other characters involvement. And just in case, I've already built his replacement(Hog Rider from Clash of Clans) if it really tanks as a concept.