get a heat gun from bunnings for about $20 bux and 2 litres of prepsol or wax&grease remover or Orange DeSolvit

first heat a fairly large area of the vinyl til very hot and especially the corner you want start with then turn off the heat gun and pick the corner and pull up slowly, then repeat until all gone should not take you longer than 15 mins to do the bonnet.

The using one of the chemicals I mentioned soak and rub the glue off.