Any ideas why my script won't change the leaderboard value?

Problem

Your problem with the script is the fact that the script can not find leaderstats in the character (Line 5). The leaderstats container is located in the player, which you do not find until line 6.

Recommendations

One thing that I do recommend you do for your script is, to detect if the hit part has a humanoid. As well as detect if the player variable had not returned nil if say, a model containing humanoid or a AI comes along and hits the brick.

Also, some of your spacing in your code is off. This progressive makes your code harder to read, by yourself and others. This may eventually lead you to forget or misplace ends for functions, loops, or if then statements.

Solution

local add = 110 --Amount of cash added when a player sits in the vehicle seat.

function touch(hit)
    local character = hit.Parent
    local player = nil
    if character:FindFirstChild('Humanoid') then --So we will check if Humanoid is in the model hitting the part.
	    player = game.Players:GetPlayerFromCharacter(character) --Now we are trying to get the player value.
	    if player then
		    if player:FindFirstChild('leaderstats') then --Now we're detecting if the leaderstats is in the player or not.
			    --With a new property released in May you are able to use a property called SeatPart in Humanoid to detect the seat you're sitting in.
			    while wait(1) and character and player do --It will wait 1 second, check if there is a character and player, if both the player and character are there, then the code will go.
				    if character.Humanoid.SeatPart == script.Parent then
					    if player.leaderstats:FindFirstChild('Money') then --Chk 4 meh m0ney.
						    player.leaderstats.Money.Value = player.leaderstats.Money.Value + add
					    end
				    else --I know what you might be thinking. What if the SeatPart is nil? Well, we don't want the loop to go on forever, so we break it.
					    break
				    end
			    end			    
		    end
	    end
    end
end

script.Parent.Touched:connect(touch) --We're connecting the function touch above this line.

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