Ceenit

I had a popping sound and the dealership diagnosed it at no charge. They ended up replacing four bolts in the undercarriage (on an '04 525) as there was a TSB on it. It's likely not the same issue on a newer car (assume they do all the TSB's before it leaves the factory). But the point is they diagnosed at no charge.

Now if they come back and tell you they can't replicate, or it's normal.....at that point, it may be worth going to a good indie to help the dealer pinpoint the issue before warranty runs out.