I've tried some of the methods that others have mentioned, but somewhere along the line I could still see where the bodywork was done. It's one of the reasons, my '55 Ford Victoria sits undone today. The roof which was heavily modified to fit, ended up ghosting even after prepping the area with Future Floor Wax.
I recommend this............
I used this on my '59 Chevy which I've posted here, and that had a TON of bodywork done on it due to the roof swap, and the opening doors and trunk.
I recommend using the this out of the can shown here, and airbrushing it on. You'll need to mix it up and it thins with alcohol if need be as it's basically a shellac. In fact, I highly recommend this for any new kit building these days, especially if you want to use the hotter automotive paints. The kit manufacturers aren't using the same kind of plastics these days...........they're softer, more pliable, and thus more susceptible to crazing than in years past.
Hope all this helps!