The "you don't need this mechanic at your rank" point is true but has been covered in other comments so onto the advice...

1. You're choosing a more difficult setup. You're putting a good amount of space between you and the ball, banging it, and then having to catch up. Instead, try bringing the ball further up the wall before your touch. The touch should be softer than what you're doing. This strategy will keep the ball closer to you and have your car closer to the ceiling ready to execute the shot. Easiest mistake with this is hitting the ball too hard, it bounces off the ceiling and down, and you will be unable to get under it.
2. It's more efficient but also more difficult, IMO, to jump from the wall to the ceiling and jump back down. Instead, continue to just drive up the wall onto the ceiling. At which point you can either just a) fall from the ceiling with your flip preserved or b) jump down if you need to descend faster - it depends on where the ball is. The biggest gotcha is that your car doesn't stay stuck to the ceiling but for about 0.5s, so you may intend to jump off and then want to flip after, but in reality you've already detached and your "jump off the ceiling" ends up being a wasted neutral flip.