I have a few rocks in my head, cuz I think I'd spend a measly $16 for those nice caps rather than taking the time to run around to an auto parts or hardware store and having to find the right size plug and hoping that it fits properly and doesn't look like an after thought cheap fix. If it doesn't fit properly having to go back to the store to return it and get a different one, etc etc.
My time is worth more than that, so to save all that time, ordering one on the internet for $16 plus a small shipping fee to get it delivered to your door and knowing it's going to work (and look good) is a small price to pay IMHO.

By the way, I know I was one of the first people on here to mention or suggest removing the sound tube. I have yet to do it.
Mainly because I have been so busy I haven't even put on the GT500 mufflers yet either. When that happens, the sound tube may come off.
But to be honest, the engine rumble has grown on me and with the stock relatively quiet exhaust, hearing the engine rumble is the next best thing.

 

Thanks, perfect timing! I just put this on my secret Santa list

 

Anyone make one sans embossed goofball logo?

 

I've got Steeda CAI and GT 500 mufflers on my GT.

With either plug out of the sound tube, it sounded really artificial. I thought it sounded OK with both plugs in, but still a little artificial.

Today I finally tried no sound tube.

With the Steeda CAI and GT500 muffs, you don't need any sound piped in, sounds much better without the tube, IMO.