I've used it on my van for almost 5 years now, no difference whatsoever with regards to the paintwork.
As has been said, it's almost the same purity as rain water.
Zero tds does not mean that that it is water without any dissolved solids in it at all, merely that measured in parts per million it is pure, if you measured it in parts per billion your meter would show a very different reading.
When a meter shows water with something like zero parts per BILLION you then have water that is incredibly pure, and will - for instance - only begin to freeze at several decrees below freezing.
The way some people talk anyone would think that pure water is bloody battery acid!
Most vehicles I believe have a clear layer on top of the actual paint, so to get through to the paint you would have to first get through this....try doing that with something like T-cut!....it'll hardly touch it.
and as for stripping off the wax coating you polish your car with...I understand that the hard wearing stuff is often silicone based??
You can also get stuff to spray onto a windscreen to repel water, and no amount of washing with either purified water or water with detergent in it will get it off, so I really can't see pure water affecting car polish that has a silicone type base.
Ian.
