One of the more frequently-asked questions in and around the M3 world has to do with aftermarket exhaust systems.  Everyone seems to accept that this is an "essential" modification, even if they might not always agree on the rationale for making the change.  Some owners are seeking outright horsepower improvements, some want a more authoritative sound note, and still others are looking to further reduce their sled's curb weight.  The result has been an all-too-predictable response from every major aftermarket supplier, and collectively, they have responded with a dizzying array of products.  

Now, I'm not about to debate the merits of what is (or is not) to be gained by selecting an aftermarket solution; much less which one might come out on top in a head to head comparison.  Everyone seems to have an opinion here, and a simple search will reveal hundreds of relevant posts on any of the leading M3 discussion boards.  More to the point, since I haven't invested in any of these products, I'm not really in a position to make a judgment.  That said, I've always found it curious that relatively few owners have ever bothered to do any research on the OEM exhaust system.  Could it be that many of our long-standing assumptions about the stock setup have been flawed?

When the E46 M3 was in development, BMW M turned to industry-leader ArvinMeritor for a dedicated exhaust solution worthy of what was destined to be the most advanced M car to date.  ArvinMeritor responded with an extraordinarily innovative and efficient design which continues to be standard fitment for every new M3.  At the time, the company prepared a fairly comprehensive 12 page document outlining the development and manufacture of the new system, but the information was never in wide enough circulation to be of much relevance to the enthusiasts down in the trenches.  

For those who might like to know more about the stock exhaust solution, I've recently posted a copy of the ArvinMeritor report (in .pdf format) to the M3 Resource web site server.  You may access it via the link provided above, or from the Featured Downloads area on the site.  Armed with this knowledge, some of you just might arrive at the conclusion -- as I have -- that your $2,000+ could probably be put to better uses elsewhere.  At least for now.  :)