Headlight warning lights come on

[KalahariBX5]

Total newbie here just bought my x5 e53 3.0. and I'm looking to get a few bits of input.

1. the headlight warning lights seem to come on at dusk and al the lights seem to be working just fine. this does not seem to occur at any other time of day. help would be appreciated.

2. what is a good product to use to get the black plastics back to their original state they are faded significantly from the sun.

thanks in advance!