To hard to describe properly without showing. guessing by your post this is relatively new to you.
I would suggest using Avery Supreme and apply the high ground flat area in the middle first.
bridge the vinyl from the high ground out to the edge of the bonnet. and tack down.
warm the vinyl and progressively stretch down the from top to the base of the recess, then apply out towards the edge.
this will stretch the vinyl across a "large area of media" that will then be applied to a flat area of the bonnet, so no pull back can happen.. meaning less tension in the recess area and thinning of adhesive on the rear.
For the record there are ways to feed the vinyl in to also relieve tension on the vinyl but too difficult to explain and requires a bit of experience.
There are lots of air escape type media on the go, some decent some poor. buy the best you can afford and price the job properly. buying cheap media will extend your fitting time and increase the chance of a fail. false economy.