How can I add cash to a play whilst they are driving?

Hello. I am trying to make a script that gives a player money while they are driving! This is what I have tried

local cashadd = 335
local distadd = 33

local owner = script.Parent.Parent.Parent.Parent.Parent.Name
local user = game.Players:findFirstChild(owner)
local data = user:findFirstChild("Playerdata")
local stats = user:findFirstChild("leaderstats")

---------- Vector Calculation ----------

function GetSpeed(part)

	pPos = part.Position; 
	wait(1) 
	oPos = part.Position; 

	pRspeed = {x=0,y=0,z=0} 
	oRspeed = {x=0,y=0,z=0} 

	pRspeed.x = math.floor(pPos.x); 
	pRspeed.y = math.floor(pPos.y); 
	pRspeed.z = math.floor(pPos.z); 

	oRspeed.x = math.floor(oPos.x); 
	oRspeed.y = math.floor(oPos.y); 
	oRspeed.z = math.floor(oPos.z); 

	IForce = {x=0,y=0,z=0} 
	IForce.x = pRspeed.x + -oRspeed.x 
	IForce.y = pRspeed.y + -oRspeed.y 
	IForce.z = pRspeed.z + -oRspeed.z 

		if(IForce.x < 0) then 
		IForce.x = -IForce.x; 
		end 

		if(IForce.y < 0)then 
		IForce.y = -IForce.y; 
		end 

		if(IForce.z < 0)then 
		IForce.z = -IForce.z; 
		end

	speed = math.max(IForce.x,IForce.y,IForce.z); 
	return 
	speed; 
end 

---------- Cash Bonus ----------

while true do
	wait()
	if script.Parent.Throttle ~= 0 and script.Parent.Steer == 0 then
		Speed = GetSpeed(script.Parent);
			if speed > 20 then
			local cash = data:findFirstChild("Money")
			cash.Value = cash.Value + cashadd
			local dist = stats:findFirstChild("Miles")
			dist.Value = dist.Value + distadd
		end
	end
end

I'm putting this in the vehicle's driver seat

edit: there is no output error

First of all, I don’t understand why you need such a complex calculation for vehicle speed when you can just get it with one line in many different ways.

Well, there’s 3 conditions your car should meet before cash upgrades. One is that, VehicleSeat throttle should be above 0, but alongside that, steer should be zero, and speed should be above 20. If one of them is not true, cash and distance will not upgrade. You should try and print each one of them in while true do, before if statements and see if they would be true if they where inside if statement. You will see that one of them is not what would meet if Statements condition. Probably that would be either speed or steer(maybe steer is never absolute zero)

---------- Cash Bonus ----------

while true do
    wait()
    Speed = GetSpeed(script.Parent);
    print(Speed)
    print(script.Parent.Throttle)
    print(script.Parent.Steer)
    if script.Parent.Throttle ~= 0 and script.Parent.Steer == 0 then
            if speed > 20 then
                local cash = data:findFirstChild("Money")
                cash.Value = cash.Value + cashadd
                local dist = stats:findFirstChild("Miles")
                dist.Value = dist.Value + distadd
            end
    end
end