hi BMW Enthusiasts

, i am new to the BMW world and obviously new to this forum.
Seeking guidance from the wealth of knowledge and experience present on this forum

i purchased a 2016 (first on road Jan 2017) BMW 435i X in May with only 41K KMS on it. i drive 100 kms a day and have already put 6K KMs on it since i bought it.
the "oil at minimum add i quart oil" message came up every 1000 to 1500 kms. i took it to my BMW showroom who kept the car 5 days and said it the turbocharger oil drain line was leaking and has been fixed. they also mentioned that thrust rod bushing is leaking too and i need to bring it back to have that fixed.
the car is under BMW warranty till Jan 2021
Question:
is it normal for a car with under 50K kms to have so many leaks ? or did i buy an abused car ?
knowing what i know now.. should i buy extended warranty.