Adding Bare metal foil to your model can give it much more realism. Bare metal foil is available in most Model/Hobby shops. It is a very thin aluminum foil with a paper backing that has adhesive on it. It is applied to any part of your model you want to look like chrome.
To me, Bare metal foil is hard to work with, but the benefits outweigh the draw backs, especially if you are contemplating trying to re-create the same effect with silver paint.
To apply, cut out a piece of the foil wider and longer than the piece you wish to apply it to. Lets say in this case, back window trim. You will need four pieces for the top, bottom and sides. I use an xacto knife to seperate the foil from the paper backing. Once I have a corner peeled up, I use a pair of tweezers to pull the entire end of the strip up off the paper. This is where it gets tricky, because as anyone who has worked with this product knows, if you just try and pull the whole piece off at one time, it is going to curl back on itself, stick together, and you will be reduced to tears in seconds. Either that, or it is going to tear, because this foil will not take abuse. Once you have an end pulled up, place your index finger between the adhesive backing of the foil and the paper backing, so the end of the foil you've pulled up will adhere to your finger. Now gently pull the foil across your fingers until the paper backing is off, and the foil is gently adhered to your fingers. This will keep it from curling. Now gently peel it off your fingers, and place it on the trim you want to "chrome." Using a fine cloth, press the foil against the piece you want chromed, but not outside of it, because you are going to have to trim it and peel off the excess. Repeat this process until you have the entire piece you want chromed covered. Your applying all of it now, because if you try and place one piece of it at a time and then trim it, you will have a hard time matching up the edges.
Once you have all the pieces applied, use an xacto knife to lightly run around the outer edges of the trim. Starting where a corner of the foil is up, gently peel up the excess all the way around the trim. On the inside, if you know the excess will not be seen, just press it under and don't worry about it. If it will be seen, trim it to where it would end on the real car. Now, using a fine cloth that will not leave lint behind, burnish the trim down all the way around. Be gentle because this stuff will tear easily. Burnishing it down will do three things: It will polish it, it will adhere it, and it will get rid of any wrinkles. If you do tear a a part of it, you can always apply a small piece over the tear, trim it, burnish it out, and no one will ever know. . .
I would say have fun, but it won't be fun. But once done, the results are worth it. . .