"Bookworm" wrote:
My plastic bath is not shining like it used to. I know I must not use
an abrasive cleaner but how can I restore it to its original shine?


According to http://www.bathroom-association.org/faq-baths.asp: Clean your
bath using only a soft cloth and warm soapy water. Rinse and wipe dry with a
dry clean soft cloth. DO NOT use abrasive compounds, pads, cloths or creams
as these will damage the surfaces.

A bit unrealistic! Do you live in a hard water area? If so, the matt finish
could be limescale. Vinegar should remove that, or any bath cleaning spray
which states on the label suitable for acrylic baths.