Plastic lenses take a lot of abuse, this is the Range Rover high level brake lightwhich looks like it has been through the car wash on more than one occasion.
Before
A hit with the wet & dry and then some G10 before finishing with A Grade
50/50
So with plastic lenses use the same procedures but go easy but omit the G3 and don't use a lot of pressure when rubbing or the plastic will melt