When painting chrome details in N scale, it is very suitable to use a silver or metallic paint, and the results will be satisfactory. However, when I started painting my N scale trucks and trailers, I started looking for something that would give me a mirror finish, for things like bumpers, fuel tanks, and possibly even a full polished stainless steel trailer. I found a product call Spaz Stix, and decided to buy a bottle. It is somewhat pricey, but wanted to give it a try. There is a lot of information about this product on the internet, and I found many photos and even videos of its application. Spaz Stix is commonly used on R/C cars, and is also meant to be airbrushed. My first test application of this paint was on a small N scale trailer, and it did seem to produce a shiny surface, although I didn't have a good smooth surface to optimize the results. What I found however was even more impressive. I use plastic pipets to transfer small amounts of paint from bottle to airbrush, and after dipping a pipet into the Spaz Stix and observing it after it had dried, it looked like shiny chrome. I wondered to myself if this stuff could be brushed on?
Well, long story short, I have been applying this product on some of my N scale trucks, and I can tell a difference between the silver undercoat and the Spaz Stix top coat. Using a brush does take some practice, as too many brush strokes simply leaves the surface dull. I am finding that a single wet brush stroke over a surface yields the best results. Another technique I am using is dipping my details into the bottle of Spaz Stix if they are small enough to fit. A good example of this is the exhaust stack on my Mack.
I don't know if this is the best product out there to produce a chrome/mirror finish, but thought it was worth a shot. I like the results, and it makes details on my trucks really pop. Try some yourself and let me know how it works.