Yeah I just bought the open sided to replace the closed ended one for my cold air intake because the top of the closed ended one is a pain in the ass to fit down there because of the fog lamp and it didn't seem like it was fitting very well. The open ended one fits much nicer down there since it is shorter. I just wanted to know because I don't want it to affect the performance with the CAI or not bring enough air in.
Your post seems helpful though. So the design is really only for the sound difference then?