Best thing for your plastics and rubber is Black Boot Polish. Reasons for this are ...
1 - Most Back to Black / Tyre Shine products are silicon based, They leave a residue (the shine) which attracts dust.
2 - Boot polish had dye in it, so it will cover up any 'fade' in your plastics.
3 - Boot polish is wax based, so even if you do get some dust settling on it the next time you drive in the rain or hose the car down the dust will run off with the water.