Not a 4Runner, but I covered this completely with Monstaliner in my garage with a roller. I've been thinking about coating the cladding on my 03 but I haven't decided yet. I researched lots of liners before I went with this stuff. It has UV protection throughout the entire liner, not just a final coat of it. It also has no fillers like rubber chunks or sand, you get the texture by letting it set up a bit and giving it a final roll so that it lifts the product up, gives it a nice "orange peel" texture. It also seals up completely so that there are no holes or voids for moisture to get in and rust the metal underneath.