It took me a couple days, but I was able to max out all four tracks. As for the ads, they aren’t forced. You’re allowed to not watch a video if you don’t want the perk of watching it. A lot of games in this style take that approach, and I can get behind voluntarily watching ads. I will say the timers for the money & speed doubler ARE BROKEN though. If you use either one once you’ll have to force close the app to get the timers to disappear once they’re actually done working, otherwise the timers will reset but have no effect and watching videos will give you nothing until you reset the app.
I’d like to see the app cleaned up, a little more content perhaps, and offline earnings are never a bad thing.