I love my 2019 X3 30i xDrive but just like /u/PenFifteen1 said, I REALLY wish I had the M40i because that sucker is so much fun to drive (can only imagine what an X3M pulls 😵‍💫). Purchased mine a year ago as a CPO (traded in a 2011 328i xDrive - I still miss it but not the constant electrical issues it was giving me) and only had a couple things replaced under warranty (O2 sensor & inside trunk buttons disintegrated… always electronic gremlins it seems!). Only thing that I need to do maintenance wise in the very near future is have the high & low temp coolant changed since it’s been 4 years. There are guides available if you search for the X3 service schedule on the Googles if you want to get an idea of what CBS is required depending upon how much you drive. Definitely get better gas mileage than my old 328i even when I’m commuting in Sport+ mode (~26 mpg). It’s been super fantastic & comfortable on long distance drives too (700+ miles in a day) and can get about 30 mpg cruising on the highway in grandma mode… errr, I mean Eco Pro mode. It still makes me smile whenever I hop in it so it’s doing its job quite well and then some. In the near future I might do a tune on it but we’ll see 😉