Savegame bug causes loss of savegame
Well, it's a great game but I've been bitten by the savegame bug that some others are experiencing too.
The game looks like it uses iCloud for save games and there is a known issue on the carmageddon web site where it doesn't always load the saved game data properly and so shows no saved games.... kill the app through task switcher and try again and it should show up...
I've had this a couple of times and restarting the app has always fixed it without losing any of my save data.
I'm guessing as it is listed as a known issue there will be an update coming soon to fix it.