Found this posted on CM forums. To get the game to start auto saving again, go to multiplayer then split screen. Choose any team and circuit. Then go to the race. when the game launches press the menu button, then go to driving controls. Then change the profile eg. from custom to keyboard or wheel default, and then create your custom set-up again, or if you used the game default one then change back to that. Quit the menu, and hopefully the autosave icon should appear again. If this doesn't work, repeat the steps on the player 2 controls. then the autosave should continue working without you having to re-start any career. I know it's not ideal and CM have said they are working on a permanent fix, but hopefully this should allow us to get further than 2 or 3 races in a career for now., Also apologies if this has been posted anywhere else, or doesn't work for some people but it worked from me and as far as i know it came from someone working at CM. So fingers crossed it'll work for everyone 
