tips and tricks
....and if you ask any real painters ( not me) there are a few things to improve your odds.
Even with a good quality stencil, it can lift anywhere it bridges panels, or, obviously, rivets. The 'vinyl' is typically more rigid, to be solvent resistant, and it likes to tent over any object. Heat will help to stick it down.
Shoot a coat of clear as your first layer, or the same as the base colour!
yep, any bleeding is nearly invisible, and you've 'sealed' the voids in the stencil.
Proceed with colour coats as desired.
Always peel before full cure, parallel to the masked line, so you shear the new paint cleanly...no lifting, stringing, messing, cursing etc. ( ask me how I learned this!)