Warning: LONG
I had heard very good things about Motor Werks west (in Wychoff NJ) from other folks. I was excited to hear that the previous owner got all of his work there but I had a questionable experience during the PPI process and I leave it up to you to decide if they are trust worthy.
The previous owner was a shipping captain and was at sea 102 days at a time (every 90 days). The car was parked for months at a time since 2003 (6700 miles). When he returned from his most recent trip in 2010 he decided to sell the car. About a months after he decided to sell, the car started running strange and had a check engine light. He took the car to his usual place, Motor Werks West where they found multiple misfires as a result of moisture being sucked in due to the same old "brake booster" issue. The car also needed a thremostat and thrust bushings.
He gave a go ahead for the work. I responded to his for sale ad around the same time the car was at Motor Werks West. We negotiated a price dependent on PPI not coming back with an unusual issues. His bill at Motor Werks was already over $2500 and he wasn't willing to budge anymore on the price of a 1 owner 2002 with 64K miles.
I spent a day looking for/researching BMW Indy shops in NJ and received multiple Kudos for Motor Werks west (also a Dinan approved facility).
I called MW and asked for their detailed ($150) PPI. They came back with Center link needing replacement, diff weeping and front rotors needing replacement in 3-6 months. I asked why the car was currently in the shop and they responded with "It needed a new brake booster and Thermostat". I asked if the car needed an oil change and I was told "no". Being the anal person that I am, I decided to ask them to change the oil so I can take a fresh start.
Long story short, I picked the car up a week later and was handed a folder of receipts. On the way back, I noticed that the service indicator only had 2 greens which seemed odd as the car just had an oil change. I called and was told that they forgot to reset the indicator.
Once home, I read through all the receipts only to find out that they never told me that the brake booster issue actually caused misfires due to moisture. They inspected the oil and did not find enough water evidence to warrant an oil drain.
I sent my oil (with 1400 miles per Motor Werks) in to Blackstone labs for analysis and the results came back with "same wear elements as seen at 5000+ mile oil".
My conclusion is that they withheld information while being paid by me for a PPI regarding the brake booster issue, they did not change the oil but charged me for it.
I cannot prove any of it and I have tried my level best to report as honestly as I can. If I was in NJ, I wouldn't be going back to them. They did not do anything illegal or even unethical. It was border line questionable but I figured I should share as they have a good reputation, which I am now old was all built by the two main M5 guys who have since left the shop and opened another one of their own.
Sorry about the long post, hope it helps