My dealer is a Dinan dealer.
I would only consider doing it there, and it was actually a reason I purchased from them (besides the aggressive pricing).
If I moved, I feel like I could get screwed.
2012 335i Mineral Gray
M Performance Whore: PPK|Exhaust|Brakes|Performance Suspension Struts & Springs|LSD|Black Kidney Grilles|CF Spoiler and Mirror Caps|Bav Stage 1|400Ms|BMWF30.com