I would like to put some ghost flames on my car, but im not sure how I would go about doing it. My car is going to be blue, right now its in grey primer. I was thinking of painting the color coat and then masking off the area around the flames and spraying a very very light mist of grey or white to the flames, and then spray the everything in clear coat. Would this be the way of doing it or is there an easyer or more effective way of painting ghost flames? Any input would be great. Thanks.

As you described- fine line tape your design, mask all other parts, use an airbrush (not detail gun) and spray right on the fine line tape lightly- the overspray will be what you are after- then clear after flashtime. I did base purple on my 'J < and red on flames, but I like doing a similar color for ghosting usually- such as slightly darker blue over medium blue. (as I am saying this I am prepping a tank for black base- silver ghost flames!!) Anything in moderation looks good!

I've heard that if first paint your flames in a metallic such as silver, copper, gold, etc., and then your main body color, you get a ghost apperance. True or false?

I would say "false". However you can get a cool effect this way depending on the colors used. You can change this effects strength by the number of coats over your ground color. Your top coats (body color) must remain translucent to get the effect.
As Dragon said, you can give the illusion of separation with a shaded line on the edge or my favorite too is to use a lighter or darker variant of the main color.
One of the main tools I use to do any graphics is to mix my main color and after all the toners are in the can I give it one swirl of a stir. this will give you an idea of the best colors to use and where to use them (as far as strength). These colors have to look good together, they are what make up this color. As an example... Dragon's car..... purple with red on the flames..... Basically. Red and Blue make Purple.... What a great combination. Don't be afraid to try things though... Anything in moderation looks good........ did someone say that already???... Bryan

Kevin posted a tank for me (problems on my end!) under 'Posted for Dragon J'- it is a red on red ghosted job and if you blow it up you'll see the subtlety- don't know if that's what you're going for but it is simple toned bases cleared. If I can do it you can!!