Yeah it could be the beading as this encourages the water to gather in tony puddles, then when you drive off it just runs off your paint. If you look at a car that's had no care the water kinda forms in 'sheets' instead.
Weve been forcast for tomorrow so I gave the bug a clean and tucked that up in the garage, so while its in there it's already had the wheels sealed again and the black gloss bits waxed - twice!!! My car will just have to sit it out!
Ps - I'm the king of the detailing nerds