The garage at Radiator Springs allows you to upgrade your cars to increase their power, and have more chances at winning extra races. Because you only can have one car at a time there, and the waiting times increase progressively through the levels, plan ahead and constantly upgrade all your cars. Do not add too many tricks and decorations to each track too soon. Certain races require a specific number of things that must be made before you can start them. Do not spend coins or gems on things that will not progress the game.