I'm going to go against the grain and say don't pre mask. It's cheap.. But your adding work and time when you don't need to.
That wrap is one of the easiest to learn how to do it without premask.... So no time like.the present to learn.
Whenever you get to a non solid piece that's been cut... Just make sure to peel slowly and support the vinyl so that it's not going to rip.
I'd be more.worried about alignment with all those grooves if you don't have experience with this type of wrap. Apply the vinyl over the grooves without Pressing the vinyl into them first. Or at least leave the last few inches where you're joining lifted... Align and repeat for the second piece. Then press into the grooves once both pieces are aligned and sticking together for best results.
If you already know this or have a different way, sorry! I think getting alignment done right would be more challenging than not using premask if you're not used to working with grooves / cut material though. An image as big as this should be fine with no pre mask even for beginners. Unless your doing it under the hot son like mentioned.