Server Script

--// Made by remi
-- Script located inside the car to give ownership.
local physicsSevice = game:GetService("PhysicsService")
local playerService = game:GetService("Players")
local replicatedStorage = game:GetService("ReplicatedStorage")
local serverStorage = game:GetService("ServerStorage")

local control_remote = replicatedStorage.ControlRemote

local wheel_template = serverStorage.Wheel

local car = script.Parent

local body = car.Body
local seat = car.Seat

local speed = car:GetAttribute("Speed")
local vertical_speed = car:GetAttribute("VerticalSpeed")
local turn_speed = car:GetAttribute("TurnSpeed")
local torque = car:GetAttribute("Torque")
local vertical_acceleration = car:GetAttribute("VerticalAcceleration")
local acceleration = car:GetAttribute("Acceleration")

local aesthethics = car.Aesthetics
local constraints = body.Constraints
local physics = car.Physics

local occupant_changed = seat:GetPropertyChangedSignal("Occupant")

local enter_prompt = seat.Enter

local current_occupant = nil

local function CharacterCanCollide(character)
    local collision_group = nil
    local massless = false

    if physicsSevice:CollisionGroupContainsPart("NonCollide", character.PrimaryPart) then
        collision_group = "Default"
    else
        collision_group = "NonCollide"
        massless = true
    end

    for _, part in pairs(character:GetChildren()) do
        if part:IsA("BasePart") then
            physicsSevice:SetPartCollisionGroup(part, collision_group)

            part.Massless = massless
        end
    end
end

local function OnPlayerLeave(player)

    local character = player.Character
    CharacterCanCollide(character)

    enter_prompt.Enabled = true
    control_remote:FireClient(player)
    body:SetNetworkOwnershipAuto()
    current_occupant = nil
end

local function OnPlayerEnter(player)
    if current_occupant then return end

    local character = player.Character
    local humanoid = character.Humanoid

    CharacterCanCollide(character)
    seat:Sit(humanoid)
    enter_prompt.Enabled = false

    control_remote:FireClient(player, "start", car, speed, turn_speed, torque, acceleration, vertical_speed, vertical_acceleration)
    body:SetNetworkOwner(player)
    current_occupant = player
end

local function Init()
    local wheels = physics.Wheels

    for _, physics_wheel in ipairs(wheels:GetChildren()) do
        local aesthethics_wheel = wheel_template:Clone()
        aesthethics_wheel.CFrame = physics_wheel.CFrame
        aesthethics_wheel.Size = physics_wheel.Size
        aesthethics_wheel.Parent = aesthethics

        local motor6d = Instance.new("Motor6D")
        motor6d.Part0 = physics_wheel
        motor6d.Part1 = aesthethics_wheel
        motor6d.Parent = physics_wheel
    end

    for _, constraint in ipairs(constraints:GetDescendants()) do
        if constraint:IsA("CylindricalConstraint") then
            constraint.MotorMaxTorque = torque
        end
    end
end

Init()
enter_prompt.Triggered:Connect(OnPlayerEnter)
occupant_changed:Connect(function()
    if seat.Occupant then return end
    if not current_occupant then return end

    OnPlayerLeave(current_occupant)
end)