Ive had the pipercross and then the k&n typhoon on my
mcs. I now have the alta and it is by far the best one out of the ones ive had. Much better design too. The gtt one is a similar design.
My first mini was a cooper and i put the pipercross induction kit on it and I got the roar and it sounded amazing.
When i got my new
mcs the first thing i did was put an induction kit on and was expecting the same roar but just got more supercharger noise which isnt a bad thing.
I then added a milltek catback which gave it more bark. The best thing for the
mcs in terms of a deep roar noise is a manifold. I have the gtt one and it sounds like a monster i love it. By far the best
mod in terms of sound for the
mcs.