Code

local seat = game.Workspace.VehicleSeat
local part = game.Workspace.Part
local bodyGyro = game.Workspace.Part.BodyGyro
local bodyVelocity = game.Workspace.Part.BodyVelocity
        local RunService = game:GetService('RunService')

seat:GetPropertyChangedSignal("Occupant"):Connect(function(hum)
    if game.Players:GetPlayerFromCharacter(seat.Occupant.Parent) then
        local plr = game.Players:GetPlayerFromCharacter(seat.Occupant.Parent)
        local currentAngle = 0

        local rs = RunService.RenderStepped:Connect(function(step)
               bodyVelocity.Velocity = (part.CFrame.LookVector  * 10)
        end)

        seat:GetPropertyChangedSignal("Throttle"):Connect(function(throttle)
            if throttle == 1 then
                print("Increase throttle")
            elseif throttle == 0 then
                print("Do nothing to throttle")
            elseif throttle == -1 then
                print("Decrease throttle")
            end
        end)

        seat:GetPropertyChangedSignal("Steer"):Connect(function(steer)
            if seat.Steer == -1 then
                print("Angle +1")
                repeat wait(.05)
                    currentAngle = currentAngle + 4
                     bodyGyro.CFrame =  CFrame.Angles(math.rad(0), math.rad(currentAngle), math.rad(0))
                until seat.Steer ~= -1
            elseif seat.Steer == 0 then
                print("Do nothing to angle")
            elseif seat.Steer == 1 then
                print("Angle -1")
                repeat wait(.05)
                    currentAngle = currentAngle - 4
                    bodyGyro.CFrame =  CFrame.Angles(math.rad(0), math.rad(currentAngle), math.rad(0))
                until seat.Steer ~= 1
            end
            print(currentAngle)
        end)
    end
end)