Nitrous bugs

When applying
If you have more than 1 bottle of nitrous in your pocket as you install it, the extra bottles will make the system think that you didn't apply it. Deleting the bottle used and not actually installing it. This will continue happening until you only have one bottle in your pockets.

After successfully applying
When you installed it and get into your vehicle and can see the "100%", you need to tap the nitrous button and reduce it to less than 100%, if you don't it will "fall off" when you exit the vehicle.

TL:DR: You must only have 1 bottle on your person as you apply or else it will poof.
You must use 1% or more to save it to your car after applying without issue.