Serious problems, whether they be in the warranty period or after, would relate to the following in my mind....

Don't have my bills here, but off the top of my head, here's what's been done, both mechanically and electrically.

Under warranty
Blower motor replaced
Front Stabilizer Swap bar replaced ($1,400 cost of part)
Fuel lock off valve? replaced
Fan motor in Pass seat for active ventilation (something like 1K - decided not to fix because WAS not under warranty period)
A/C Compressor...seems to soon, but I'll be a sport....
CCC unit - by my direction to fix a problem
iDrive screen - by my direction to fix a problem
Bluetooth module - by my direction to fix a problem
CAS Unit - by my direction to fix a problem

...(*by my direction to fix a problem) - problem has not been fixed.

Smaller issues:
Right front strut top replaced ($600 plus if memory serves me right)
Twice, vertical window pillar trim replaced
Twice, door molding replaced
Steering wheel button plastic replaced
Once, upper trim, glove blox replaced
Once, entire glove box replaced (FYI, noise still there)
Rear parcel shelf, replaced

Other things that I have had replaced:
TWO - windshields
One rear window

This does not include regular tire replacement or any additional items put into my X.

Let me stop all the nay-say'rs out there that will criticize my post as complaining. I am not, just merely explaining what constitutes serious issues from smaller ones as per the question posed. I have a BMW, I'm prepared with the costs, its just that over the past 12 months, problems and issues have arisen too frequently and a general frustration has grown with the situation. I'm sure my next car will have issues, it all depends on the environment surrounding the causes and the way in which they are corrected.

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