I've been playing this game for a while but I'm really frustrated by the amount of game crashes that I get. I use an iPAD 3 with a stable WiFi connection and usually when I close and reopen the game i loose about 4/5 gas pipes just to get a stable race.
Another things that bugs me a lot is when I spend the cash to buy some upgrade or trick. If I don't have an extra 2k/3k than the required amount the game will send me an out-of-sync message, reloads and I will get a less amount of cash than I previous had.
Finally, one thing that should be improved is the amount of time each trick takes. If I try to do a 95 point trick time it will take a very short amount of time compared to an 81/85 trick point.
Besides this problems that I hope will be solved the game itself rocks. It's well done, nice graphics, awesome playability and a good game to spend some time daily.