As others have mentioned, Oracal 651 is a permanent vinyl that can be used for car decals.
I personally make them with this vinyl.
Oracal 631 is a temporary vinyl with a water soluble adhesive, so while it will stick fine for a while, it will not stay on for a long period of time due to rain/car washes/etc.
Can a Cricut make car decals?
If a big mouth bass isn’t your thing, you can turn any cut image into a window decal using the Premium Outdoor Glossy Vinyl. You can pick an image from Cricut Design Space if you’d like, but I’m going to show how to upload an image and create your own cut file.
Can you use permanent vinyl for car decals?
Most permanent vinyl has a glossy finish, but not all (Oracal 641 is a matte vinyl with a permanent adhesive). Permanent vinyl can be removed, but it may do damage to walls, paint, etc. Removable indoor vinyl is great for wall decals, indoor signs, stencils, and any time you want a temporary application.
What is the difference between 651 and 631 vinyl?
For ORACAL products, the adhesive on 631 vinyl is clear, water-based removable adhesive while 651 is clear, solvent-based permanent adhesive. The finish on 631 vinyl is matte while 651 is glossy and also available in matte in black and white only.
Photo in the article by “Wikimedia Commons”