glenmore- Good for your Brother-in-Law. The interior of the new TL is very nicely built. As far as the break-in is concerned, someone in the M5 forum-I can't seem to find the link- suggested a 2000 mile rule. For the first 500 miles, drive the car mildly, never exceed 3500rpm. For the next 1000 miles, gradually increase the engine speed and vary load patterns on the car. For the final 500 miles, he suggested drive the car as agressive as you never will, such as full trottle. After that, you can just switch back to your normal driving habits. In regards to the engine oil, I would switch over to synthetic oil after the initial 6000miles, as suggested by the mobile 1.