Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
All mine fill up don't worry to much just enjoy the sound track.You could always fill them with oil but they would smoke a bit when refitted.I won't be swapping mine for aftermarket pipes. Why would you want to hide them away?
Actually you are possibly right, there is a small hole at the end of the pipes I believe to allow breathing, but next to useless.