Hi I have an non s mini cooper 03 and I love it!

I want to upgrade little by little on this car. For far I just replaced the air filter for an K&N filter it's seems to work good.

Now I do consider of getting a ddm works cold intake on it.
But later on.

I like to get a John cooper exhaust system. Would it work on my standard mc?
Do I need anything else?
Would you refer anything else other then a jmc exhaust system?

I don't want it to sound like I'm farting or sound stupid I was something easy but a nice increase.
Please help me here thanks