I am looking to get custom quad exhausts on my 540i. From what I
understand, I can use a muffler with one inlet and two oulets to
achieve this(Magnaflow makes the 12267 Muffler), with one pipe
circling back around and exiting on the other side of the vehicle,
similar to this:


OR



This is the look I am going for:



If you could, I would like a quote for the exhaust if I bring my own
parts (i.e. muffler, and tips) or a quote if you supply the parts.