I just bought four old motor oil cans at an estate sale that I plan to sell at a later date. They are in overall pretty good condition, (no rust), but I'm thinking about waxing them with some car paste wax. Will getting them 'shiny' destroy the value? Please advise. Thanks.

IMO,
getting them "shiny" will increase the value,
be careful on the earlier litto'd cans
use a straight wax with NO cutter .. ...

Thank you. Do you have a brand or brands you would recommend?

I wax all mine including the cardboard cans. I use liquid Turtle Wax.