I noticed what looked like long, wiggly worms appearing all over all four (standard) wheels of our 2008 Volvo C70. They seemed to be radiating from the hub across all the ’spokes'. Neither the Volvo main dealers nor our local first class independent garage could identify the cause. Cleaning them (hard) made no impact at all as the very metal of the wheel is scarred with these bizarre, raised lines.

After many months in the dark, I was queuing at a local carwash and I saw the guys squirting a cleaning agent on the wheels of the car in front from a thin-nozzled bottle. My suspicions suddenly aroused, I asked the guv’nor what he thought might be the cause of these ‘worms’ on my wheels. He immediately replied, “it's this stuff” - meaning the wheel cleaner. To demonstrate his point, he squirted some on the tarmac and within a second, smoke started to rise from where it landed. Clearly, unless it is washed off with copious amounts of water immediately, it will penetrate the clear-coat lacquer on most alloy wheels.