Some advertise that they will put in the date codes,but I am not sure that anyone is totally happy with the aftermarket glass. If your originals are not scratched you can polish them just like paint and make them new again. I know that I looked high and low for one replacement that was scratched and ended up replacing both door glasses so they match. I do have a few extra pieces and sometimes you can match them up if you have a bad one. The new pieces are lighter and definitely of different composition. You may be happy if you buy all new pieces,but they do not match originals as far as I have seen.