If you decide to eventually put the cutter to other uses and start making vinyl signs, decals, etc., on the side, I wouldn't use that vinyl. Use it all up for your screens, or for things to be used indoors. That deal is good enough with all the other items you get to go for it anyway, but if you're planning on selling car decals, especially if you wind up doing things like logos for a fleet of company cars, I'd order Oracal 651 vinyl for flat items and Oracal 751 for curved surfaces and going over rivets, etc. That same company has decent prices on that direct from their website.
Using vinyl that's too cheap can result in quick delamination even if the surface is properly prepared, or if it does stick, fading, cracking, and difficulty removing it to re-do the job. You really want to use cast vinyl, not calendered, for most projects, but Oracal 651 is a calendered vinyl that consistently gets excellent reviews. Mostly flat surface use only, though (the slight curve of a rear window, etc, is fine).