I believe that everyone who used glow effect (eighter in Render\Effects\Lens Effects or in Video Post) had problems with making objects glow behind glass/transparent objects (ie. glowing lamp behind a glass window or car headlights). Well, there is a solution to this problem and you can get an interesting freeware plug-in called Throuhout here:
Unfortunately the site is in russian only, but believe me this is worth getting! If any questions arise about using this simple plug-in be free to write.
And big THANKS to the guy who wrote the plug - Pavel Kuznetsov