How to avoid the Spiny Shell

So you're in first place. You see a warning that a spiny shell is going to hit you. Here is how to avoid it.

For this, you must have a mushroom!!!! As soon as you see that the shell is coming down toward you, use your mushroom. This will get you away from it, and it will blast behind you.

Or

If you're close to a cannon, get there as quick as you can. If you get there in time, the spiny shell won't hit you. If you're there late, it will hit you. The following courses have cannons or things that will cancel the spiny shell's blast on you.

DK Summit: The DK Cannon after the first turn.

Rainbow Road: The cannon between the 2 giant stars.

N64 DK's Jungle Parkway: The speed boosts that shoot you over the yellow river.

GCN DK Mountain: The DK Cannon after the first turn.

Maple Treeway: After the first couple turns.