A deep clean.
For Vinyl revival to work its best, the surface needs to be clean. Do this job in the shade, out of direct sunlight. Rinse the tonneau down well with water, then spray the Sublime Clean onto the area you wish to clean. You don't want the Sublime Clean to dry, so work on smaller areas on warmer days, like half the Tonneau or less if its a warm day. We prefer using the Sublime Clean over our all purpose cleaner Orange Agent as it's a lot more forgiving if it dries.
Gently clean the surface using our Plush Brush for the best clean, or even a Love Glove wash mitt, in a side to side overlapping east-west and then opposite north sount motion to ensure you clean all the undulating surface of the tonneau.
Then get our Big Boy Brett detailing brush from The Foursome round brush set, spray Sublime Clean into it and do the joins and edges where there is stitching.
If the tonneau is really dirty or mildew infested, it may need to cleaned twice.
Finish by rinsing the Sublime Clean away with your hose and moving onto the next section, till you're all done. Sublime Clean will not affect paint or your waxes, sealants or coatings either, but still make sure it is rinsed from the side panels of the car before moving to drying it all down.
Wash both brushes out in fresh water as well, store both brushes Plush Brush with the bristles facing upwards, or hang them where they won't be affected by other things leaning on the bristles.