Various Gameplay Tips:

Tip 1: Your track can only have a certain amount of cars driving on it at a time. If your track hits its cap, you'll activate a +10% coin bonus, but ONLY if your track remains at its cap. If you remove any cars, you'll lose the bonus. This is easy to manage early on, but every time you level up you'll unlock additional slots on your track and it becomes harder to manage. You don't have to worry so much about this if you're planning on actively playing the game. If you are going to step away from a period of time, be sure to fill up your slots before you leave so that you generate bonus coins as you're away.

Tip 2: Even if you don't actively purchase any new cars, the game will automatically deliver a free level 1 car to you after about 30 seconds of in-game time. You don't even have to manually open the packages they come in - those open by themselves after a couple seconds too! If you're low on coins or if you just want to save up, then be patient and just wait for the game to hand them out to you. You don't need to have the game open either, as they'll collect over time when you're away from the game. The best part about this is that once your level gets high enough, you will have a chance to get level 2 cars instead! Keep leveling up for better, free cars!

Tip 3: You can buy specific level cars by tapping on the button with the three cars on it. You need to be high enough level first, though. One important thing to note is that every time you buy a car through this method, its price is permanently increased. If you're going on a merging spree, you should check the prices to make sure your spending your coins efficiently. Let's say for example that you have the option to buy both level 1 and 2 cars. You buy a ton of level 1 cars but no level 2 cars because it's cheaper at the moment. Because of all the level 1 cars you've bought, the price for them has skyrocketed and now it's cheaper to buy level 2 cars. Pay attention to the prices, and be sure to spread out your purchases so that you don't make one specific level car get too high.