Dealership Aftermarket Shop vs. Independent Aftermarket Shop

[jmflukeiii]

The dealership I bought my M3 at and whom I've always heard incredible reviews about, and have given an incredible review about myself, has its own aftermarket division that operates independently from the dealership, but must be owned by the same people or something along those lines. This dealership has 5 different franchises, one of them being BMW.

My question is, I feel almost more comfortable having work done at a place like this, that is dealership recommended (obviously, because they own it), makes me just feel more comfortable about the work being performed on my car. Is there any justification for this feeling or will ultimately be more expensive?

So far, the guy who worked with me to actually get my car has been very good about not "selling me just BMW stuff"... i.e. I asked about the M performance exhaust and he said that its highly over-priced, yada yada, and that there's much better aftermarket alternatives. My point being that I've been incredibly pleased with his help so far, from a knowledge perspective, and from a "being honest" standpoint about my options.

This shop at the dealership has also now offered me a full Dinan exhaust set-up "at cost" which I'm not entirely sure what price that means.