RESOURCE PACK NOT NECECARY BUT IF USED, REQUIRES OPTIFINE!
Simple datapack, simply unzip, stick in your datapack folder, reload and instructions of use are provided ingame.

This datapack turns minecarts into cars. I believe it to be useable in multiplayer but if it is not please tell me.
The way it works, is you get in a minecart, put green / lime wool in your offhand (different wool for different speeds) and it moves the minecart you are in.
You can rotate with an arrow or bone and it only rotates the minecart you are using.
Minecarts automatically teleport up to the highest block when colliding into pillars and snap down to the floor if freefalling.

This datapack does not affect default minecarts if not holding items to move minecart as a car in offhand, appart from lifting the player 1 or 2 blocks off the floor in the minecarts. (This is due to the teleporting up command, I might figure out a fix later.)

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-Updated 4th April 2022 - Code optimisations and improvements in attempt to fix multiplayer controlling every cart players are in, tried to make it each players only controll their minecart. If there are still problems, please comment here to let me know.

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- Updated 27 march 2022 - added a function to give stuff: "/function cars:give", this will give the 4 items and summon a minecart at your exact position.
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- Updated 27 march 2022 - added a trigger to trigger the function. Type /trigger givecars to activate /function cars:give and gain the 4 items and spawn a minecart.
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- Updated trigger to display "how to use" instructions which are displayed when you reload.
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-Updated 27 march 2022 - Added reverse (red wool) and speed 3 (green concrete powder), gives red wool and green concrete powder on /trigger givecars, a "/trigger summon" to summon minecarts and a couple code optimisations. Text upon /reload and /trigger give updated to include the new speed and reverse blocks. PLEASE NOTE THE RESOURCE PACK MAY ONLY WORK ON OPTIFINE!
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- Updated 28 march 2022 - Resource pack made: Adds steering wheel to minecart, moves the minecart wheels to be accurate with movement direction, Rotates arrow by -90 degrees, adds arrow tip to Bone texture to make it more obvious as direction pointer