Rain Aid is a glass hydrophobic treatment that bonds to the windscreen and side windows to create a rain-repelling barrier. Above around 30mph, water sheets off the screen and dramatically improves forward visibility in wet weather. It also makes insects, road film, and general contamination much easier to remove during the next wash — they can't grip the treated surface the same way. One application lasts 8–12 weeks depending on conditions and wash frequency.

How to use: Apply to completely clean, dry glass — any contamination or residue under the treatment will prevent it bonding properly and cause patchy performance. Spray Rain Aid onto the glass and spread evenly with a clean microfibre cloth in straight strokes. Allow to cure for 3–5 minutes until it begins to haze slightly, then buff off with a dry microfibre in circular motions. For maximum performance, apply a second coat once the first has fully cured (allow 10 minutes between coats). Reapply when beading performance reduces — typically every 2–3 months.

Tip: Apply to all glass surfaces including side windows and rear screen, not just the windscreen. The improvement in visibility on side windows when it's raining is underrated — especially at motorway speeds.