*NEW* Earn Loads of Money in Manger Mode (Career)
1. Make a loan offer for a player you're sure you'll get. Just go for a bad player. Make him an offer he can't refuse.
2. Sign him up when he accepts.
3. Go to budget allocation and set it to 0:100 (ie. no transfer funds; all allocated to wage budget)
4. Go to sell players, and cancel the player's loan. You'll now see you have a negative transfer budget.
5. Go back to budget allocation, and set it to about 40:60. Finished.

IMPORTANT
-Don't do it again (unless you've spent all your cash!). You won't get any more money, it just sets back to the same amount. Plus you can only change the budget allocations a few times so don't 'waste' them.
-Do not try to set it to maximum transfer budget (which is about 50:50; I think the figure is about 2,147,000). If you do this, making any money will glitch the budget in the opposite direction, meaning you'll find yourself 2 billion IN DEBT if you sell a player, for example. Be conservative- About 1.5 billion should be heaps, and will be safe from this glitch because you won't earn 600mil