This is usually not a problem for me because it's a sweet, low sound and I love it, it's not leaking or broken. But when going for longer drives, as in more than 30-40mins, the sound gets on my nerves, so I was wondering if there's anything I can do about that ? Maybe an external silencer which I can put on the muffler then take it off ? I don't really want to put the stock exhaust back on. I also have the Buschur muffler which makes it even louder than the ones with the Magnaflow muffler.
Let me know what you guys think.

BTW: Sorry if it's in the wrong section.

 

Okay so you say you like it but get's on your nerves when driving for a long period of time. Understandable, lol.

What's your setup right now, do you have a resonator on it? As for a silencer, yes it is an option if your exhaust compliments one. Some exhausts on the market bring a silencer. That's pretty much all I can think of that can possibly solve your problem. If there's not silencer for it, you're pretty much stuck w/ your exhaust

go back to stock if you don't like it..

 

Try looking into some kinds of insterts that would go inside the muffler tip. They are called "silencers".