We have two products that will work on a tonneau cover.
1) Our Tire Shine Spray - this is the more simple application as it's an easy-to-use spray and wipe product.
2) Our Plastic Restorer - this takes a bit more time as you need to apply it with the included applicator, however, we recommend this over the Tire Shine as it's a bit more durable.
Both products contain durable UV protection and both products dry to the touch so there should be no run-off if applied correctly. After application, you need to wait about 10-15 minutes and then we recommend to completely buff it off after with a microfiber towel to get all the excess off. This will prevent any future run-off in the rain.
If some accidental application occurs on your paint, you can simply wash it off, no harm should be done to your vehicle as all our products are non-toxic and eco-friendly.