I use it on all my tires for a very natural rubber look, even on my delivery trucks. I don't like the unnatural glossy look of other tire treatments, and I don't like any possibility for silicone sling and associate paint damage.
Keeping in mind I live in the Pacific Northwest where it drizzles constantly from October through June, one application of 303 only holds up about a week or so on tires, and the looks can degrade more when exposed to mud. It is so quick and easy to apply, another treatment might take five more minutes.
However, I also use Aerospace 303 on my pickup truck tonneau cover which is exposed to the same rains, but not the mud, and it lasts for months. The same durability is true with almost all other black plastic trim pieces including the backs of mirrors, window rubber weather stripping (avoid getting it on the glass, though), windshield wiper cowling, bumper trim, etc. I have also used it to cure a window squeak as the rubber weather stripping aged. While I don't know how long the squeak is banished for, it has already been the better part of a year.
With our Macan, the jury is still out on durability given how low the side blade is on the body, but a once-a-week touchup, if necessary, could not take more than a minute or two. Even so, 303 would be my treatment of choice as it makes the plastic look brand new with almost no effort.
A couple of cautions from experience: (1) in delicate areas, especially around glass and paint, spray 303 on your rag instead of the part itself to keep from getting it where you really don't want it, and (2) don't allow 303 drips or overspray to fall on your driveway because it will show up as a dry spot in the rain for *months*. I guess this might be a back-handed testament to its general durability. We have a carefully maintained blacktop drive, and any 303 that gets on the driveway is pretty much there until it is covered over the next time we retreat it.