re: the login bonuses...
Manual save seems to work for some, but I have heard that you need to at least do something too, like switch cars and trigger an "event".
Also, consider the real-world 24hr period you login. If you let the entire next 24hr period lapse (from 00:00 to 23:59, not based on your last login) then you lose a day of your bonus. Depending on when you login, you could actually lose two days worth of bonuses when it seems like you should only lose one.
Also, also, I do not yet know whether the login bonus happens again automatically while in-game if the day changes while you were playing, such as logging in at 23:00 and then going back to main menu without exiting game, after 00:00. GT5 would trigger another bonus and you just had to make sure it saved. Now, I'm not sure, but I think it doesn't trigger a new bonus. Exiting the game and coming back would do the trick, though.