This is the same muffler that Che (Deluboz parts out of Dallas) gave me to put on my car and test four years ago. It was crooked too when installed, but my mechanic just used a crowbar to bend one side of the muffler up and straighten it out. That's not a big deal.
It sounds great with the top down, but with the top up and windows up, the resonance between 2-3k rpm is awful. Whenever I'm now caught in the rain and forced to raise my top, I dread it.
My wife no longer enjoys riding in the car with me and everyone who rides in the car says "that muffler sure is LOUD. How do you drive this car without experiencing hearing loss?" And when I drive in high rise parking garages, I set off alarms left and right with the vibration the sound causes.
Now temper all this with the fact that if you avoid putting around in town in the 2-3k rpm range the resonance is absent. So if you don't drive your car to work or for errands and you never sit in traffic, it's not that big of a deal.
However, whenever I have someone in the car and I want to speak to them or make them feel comfortable, I'm constantly upshifting or downshifting to get away from the resonance issue.
At redline, this muffler sounds glorious. Absolutely glorious. So at the track I know exactly when to shift without looking down at my tach, even while wearing a balaclava and a helmet and having an instructor screaming in my right ear about how poorly I am driving most of the time
The problem with all these twin chamber mufflers for our cars (regardless of price) is that they experience nasty resonance at 2-3k rpm. I've yet to see one advertised as a better sounding, louder muffler for the boxster that is guaranteed to have the resonance engineered out of it. I don't think they exist. Now the Dansk Porsche approved sport muffler is different because it's a modified single chamber unit.
Upside: This thing is a fraction of the weight of your factory muffler and your trunk won't get super-hot if you install it.