I've used Alclad and Mirrachrome for several years and have had great luck with it. You don't really want to clear coat over it and if you apply it over the proper base coat, you won't need to anyway. The best base coats for Alclad Chrome that I've tried are Testors gloss enamels, especially black or gray, or Alclad's Glossy Clear Base (ALC 303). The real trick here is to get the surface as smooth and glossy (like glass) as you can before you mist on the Chrome. If you spray the chrome over a black base, you may have to apply it in two sessions or it might look a little dark, like nickel plating. If it's still not quite reflective enough for you, you can use a soft clothh to rub it out a little. This also removes the "dust" that Alclad sometimes leaves on the surface. If you spray this over an enamel or their clear base, you're not very likely to rub the Alclad off, but when I;ve sprayed it over a gloss lacquer base like Tamiya spray-can gloss black, the Alclad is prone to rubbing off.
Another trick I like to do is rub the chromed surface with a little SNJ Polishing Powder (either aluminum or steel) with a soft cloth or a Q-tip and that often adds a little more luster to the chrome. Chroming with Alclad isn't exactly like factory kit chrome plating because the mehtod is sompletely different. However, I think it looks more realistic than factory chrome anyway, and besides it's a lot of fun!