Have been looking for similar products on ebay and there is nothing of 500ml for a fiver or less.this looks good.
Ultimate car care
Apply regularly through cold weather
Easy to apply
Enhanced visibility, safer driving
This Mer rainaway rain repellent is specially created to prevent rainwater sticking to your windscreen and car windows, rainaway is ideal for the long haul. With this rainaway, visibility is radically improved, making your journeys safer and less stressful, especially on motorways. Also with this formula, you don't need to use your window wipers all the time, saving wear and tear on your wiper blades.