"TIP: If you’re having a hard time with a level, try only going for a couple coins at a time rather than all at once. Doing 5 runs of a level grabbing 5 coins each time is much easier than one monster run for all 25 in one shot."
I dont think that would help in lvl 40.
The trick to getting lots of money at the start is doing perfects. When going down the hill, basically manage to get in the yellow area for both parts. If you do, you will be awarded 1000.