In two spots on my upper rack, rust is starting to break through the vinyl coating. Is there a product to prolong the effect of this, so I don't have to invest in a new upper rack?
There is. There is a appliance paint you can use.
I have used it on two different dishwashers and the result wasn't that great.
I found you had to keep applying it.
If it is just the tops of the tines I belive there are little tops you can get that slide over the ends.
The rack in my kenmore dishwasher not only rusted the tines just came off.
After 7 came off I had to buy a new rack.
it was over $100.00.
There's also a liquid vinyl coating that you can buy at Homo Depot or Lowe's. It's available in spray or liquid(use the liquid). Unfortunately, it only comes in white, black, blue, red and yellow, so if the Miele racks on your model aren't white... It works well, but you have to let it cure for a while. I've also used a wire cutter to surgically remove rust spots on racks and then capped the cut ends off with those little plastic cap ends that you can also buy at hardware stores.