Here is the method for changing the time zone to get the 200% login bonus. As posted in another thread of a similar name:
1. Enter the game normally, receive the 110% bonus.
2. Save the game by changing into a different car and letting the game save automatically after.
3. Open the XMB, go to Time and Date Settings under Settings far left before Users, this will need the game to quit.
4. Go to Time Zone. Change this so that wherever you are your PS3 clock will show just before midnight.
5. Enter the game, wait until past midnight, accept the next bonus, repeat steps 2-5 again until you're at 200%.
Some time zones are in half hours and quarter hours, so that will speed things up even more.