Deep cleaning products

[Dram]

Decided to do a deep clean of our van & discovered what appears to be slight yellowing stains around the plastic shelf, which is part of shower enclosure. Have a similar problem in the fridge, which I assume is slight yellowing again , on the plastic interior of fridge , may have been caused by slight rusting of the coated wire shelves. Any advice , would be much appreciated

 

[David and Sally]