DarkSide is the step up from a diluted dressing like Perl when you want the tyres to stay dark through the wet. CarPro US calls it much more durable on tyres, especially in wet conditions, while Perl stays the more versatile, dilutable choice for trim and interiors.
The finish is satin rather than a wet-look gloss. CarPro US notes the gloss fades over time while the tyre stays cleaner and keeps repelling water.
CarPro credits its 60% polydimethylsiloxane formula for the quick, easy application, and CarPro US says its UV protection guards the rubber against degeneration.